Balochistan Mdcat 2025 — Solved Past Paper with Answers

Q1. The magnitude of electric field intensity due to a point charge q at a distance r in vacuum is given by

• A. E= q/r2
• B. E= kq/r
• C. E= kq/r2✓
• D. E= k/r2

Explanation: The correct answer is E= kq/r2, which is derived from Coulomb's law, stating that the electric field (E) created by a point charge (q) at a distance (r) in vacuum is proportional to the charge and inversely proportional to the square of the distance from the charge. The constant (k) is Coulomb's constant, which adjusts the units appropriately. - Option A is incorrect because it does not include the constant (k), which is vital for the correct formulation. - Option B is incorrect as it misrepresents the relationship by using r instead of r2 in the denominator. - Option D fails because it omits the charge (q), thus providing an incomplete expression for the electric field.

Q2. If the angle between force and velocity is 90°, the power delivered by the force is

• A. Zero✓
• B. Maximum
• C. Minimum but not zero
• D. Infinite

Explanation: The correct answer is zero because power is calculated as the dot product of force and velocity. When the angle between the two is 90°, the dot product is zero, meaning that no work is done in the direction of the velocity. Option B is incorrect because maximum power occurs when the angle is 0°, not 90°. Option C is also incorrect as it implies there is a minimum power that is not zero, but when the angle is 90°, power is definitively zero. Option D is incorrect because power cannot reach infinite values; it is bounded by the definitions of work and time.

Q3. Bermoli's principle helps explain why blood pressure drops when blood velocity

• A. Increases in narrow vessel✓
• B. Decreases in narrow vessel
• C. Increases in wide vessel
• D. Decreases in wide vessel

Explanation: Bermoli's principle illustrates that as blood velocity increases in a narrow vessel, the pressure decreases due to the conservation of energy and the increased resistance encountered by the blood. This principle is specifically applicable to narrow vessels where a reduced cross-sectional area leads to higher velocity and lower pressure. Therefore, Option A is correct as it accurately reflects this principle. In contrast, Option B is incorrect because a decrease in velocity in a narrow vessel would typically result in an increase in pressure. Options C and D are also incorrect; they misinterpret the effects of vessel diameter on blood velocity and pressure. In wider vessels, increasing velocity does not generally lead to a pressure drop, and decreasing velocity does not create significant pressure changes due to the greater capacity for blood flow.

Q4. A string vibrates in the first, second and third harmonics. The ratio of their wavelength is

• A. 1:2:3
• B. 3:2:1✓
• C. 1:4:9
• D. 3:6:9

Explanation: The correct answer is 3:2:1 because in a vibrating string, the wavelength of the harmonics is inversely proportional to their harmonic number. The first harmonic (fundamental frequency) has the longest wavelength, while the third harmonic has the shortest wavelength. Thus, the ratio of the wavelengths is 3 (first harmonic): 2 (second harmonic): 1 (third harmonic). Options 1:2:3, 1:4:9, and 3:6:9 incorrectly represent this relationship, either implying direct proportionality or incorrect mathematical relationships.

Q5. If the length of the copper wire connected in a circuit is doubled, it's resistivity

• A. Becomes half
• B. Becomes double✓
• C. Becomes four times
• D. Remain same

Explanation: When the length of a conductor like copper wire is doubled, its resistance increases proportionally. The resistance (R) of a wire is given by the formula R = ρ(L/A), where ρ (rho) is the resistivity of the material, L is the length, and A is the cross-sectional area. Since resistivity is a material property and does not change with length, when the length (L) is doubled while keeping the area (A) constant, the resistance doubles as well. Therefore, the correct answer is that the resistance becomes double. The other options are incorrect because they misinterpret how resistance varies with length.

Q6. On increasing the length of a wire, the specific resistance (resistivity) of the wire

• A. Increases
• B. Decreases
• C. Remains unchanged✓
• D. First increases, then decreases

Explanation: The correct answer is that the specific resistance (resistivity) of a wire remains unchanged when the length of the wire is increased. Specific resistance is a property that depends solely on the material of the wire and is not influenced by physical dimensions such as length or cross-sectional area. Therefore, options A, B, and D are incorrect as they suggest a relationship between length and specific resistance that does not exist.

Q7. The efficiency of an emf surface becomes 50% when the load resistance is equal to

• A. Internal resistance✓
• B. double the internal resistance
• C. Half the internal resistance
• D. Zero

Explanation: The efficiency of an emf surface is defined as the ratio of the power delivered to the load to the total power supplied by the source. At the condition where the load resistance equals the internal resistance, the load receives half of the total power, resulting in 50% efficiency. The other options illustrate scenarios where either the load resistance is too high or too low in comparison to the internal resistance, which leads to inefficiencies. Therefore, the correct answer is when the load resistance equals the internal resistance.

Q8. Each DNA nucleotide differs from the others based on its:

• A. Nitrogenous bases✓
• B. Phosphate group
• C. Sugar molecule
• D. Number of phosphorus atoms

Explanation: Each DNA nucleotide is composed of three parts: a phosphate group, a deoxyribose sugar, and a nitrogenous base. The nitrogenous base is what differentiates one nucleotide from another. The four types of nitrogenous bases found in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). While the phosphate group and sugar are consistent across all DNA nucleotides, the varying nitrogenous bases provide the unique characteristics necessary for genetic coding. This is why Option A, 'Nitrogenous bases', is the correct answer. The other options (phosphate group, sugar molecule, and number of phosphorus atoms) do not account for the uniqueness of each nucleotide, as they remain constant across all DNA nucleotides.

Q9. Two standing waves vibrate in fundamental mode in two two organ pipes A (open) B (closed) each of length 60 cm. The ratio of frequency of A to B is

• A. 1:2
• B. 1:1
• C. 2:1✓
• D. 2:3

Explanation: The frequency of a standing wave in an open organ pipe is determined by the equation f = v / (2L), where v is the speed of sound and L is the length of the pipe. For a closed pipe, the relationship is f = v / (4L). Given that both pipes A and B have the same length of 60 cm, we can see that:For the open pipe A: f_A = v / (2 * 0.6) = v / 1.2For the closed pipe B: f_B = v / (4 * 0.6) = v / 2.4Now, taking the ratio of the frequencies:f_A : f_B = (v / 1.2) : (v / 2.4) = 2 : 1This confirms that the frequency of the open pipe A is twice that of the closed pipe B. Therefore, the correct answer is 2:1. The other options are incorrect because they do not reflect the proper frequency relationships dictated by the pipe configurations.

Q10. Which of the following is the causative agent of Gonorrhea?

• A. Herpes simplex virus
• B. Treponema pallidum
• C. Mycobacterium tuberculosis
• D. Neisseria gonorrhaeae✓

Explanation: Gonorrhea is caused by the bacterium Neisseria gonorrhaeae, which infects mucous membranes and is primarily transmitted through sexual contact. The other options presented are causative agents of different diseases: Herpes simplex virus causes herpes, Treponema pallidum is responsible for syphilis, and Mycobacterium tuberculosis causes tuberculosis. Understanding the specific pathogens associated with various sexually transmitted infections helps clarify their identities and implications for health.

Q11. Cholesterol and phospholipids are mainly synthesized in liver cells by:

• A. Golgi complex
• B. Mitochondria
• C. Rough endoplasmic reticulum (RER)
• D. Smooth endoplasmic reticulum (SER)✓

Explanation: The correct answer is Smooth endoplasmic reticulum (SER) because this organelle is crucial for the synthesis of lipids, including cholesterol and phospholipids, primarily in liver cells. The SER lacks ribosomes, which distinguishes it from the rough ER, and it plays various roles in metabolism and detoxification.The other options are incorrect for the following reasons:Golgi complex: While it processes and packages lipids, it does not synthesize them.Mitochondria: Their primary function is energy production, not lipid synthesis.Rough endoplasmic reticulum (RER): It is involved in protein synthesis and has ribosomes, limiting its role in lipid synthesis.

Q12. 0Water flows through a hoizontal pipe with area of 0.02 m2 at 3 m/s. The pipe narrows to 0.01 m2. The velocity in the narrow section is

• A. 0.5 m/s
• B. 3 m/s
• C. 1.5 m/s
• D. 6 m/s✓

Explanation: According to the continuity equation, the product of the cross-sectional area (A) and the velocity (V) must remain constant along a streamline. This can be expressed as A1V1 = A2V2. In this case, we have:A1 = 0.02 m2, V1 = 3 m/s, and A2 = 0.01 m2.Plugging in these values:0.02 m2 * 3 m/s = 0.01 m2 * V2Solving for V2 gives:V2 = (0.02 m2 * 3 m/s) / 0.01 m2 = 6 m/s.Thus, the correct answer is D: 6 m/s. The other options are incorrect because they either suggest an incorrect relationship between velocity and area or do not apply the continuity principle correctly.

Q13. The molecules that has non zero dipole moment is?

• A. CO₂
• B. CO✓
• C. BF₃
• D. AlCl₃

Explanation: The correct answer is CO because it has a permanent dipole moment due to the difference in electronegativity between carbon (C) and oxygen (O), resulting in a polar bond. In contrast, CO₂ has a linear geometry that cancels out the dipole moments, making it nonpolar. Similarly, BF₃ and AlCl₃ are both symmetrical molecules; thus, they also exhibit no net dipole moment, leading to a total of zero dipole moment.

Q14. Unit of rate constant for a particular reaction depends upon the:

• A. Temperature of reaction
• B. Activation energy of reaction
• C. Molecularity of reaction
• D. Order of reaction✓

Explanation: The correct answer is Order of reaction (Option D) because the units of the rate constant (k) are derived from the rate law, which is based on the reaction's order. For example, for a first-order reaction, the unit of k is s-1, while for a second-order reaction, the unit is M-1s-1. Thus, the order of the reaction directly affects the units of the rate constant.Options A, B, and C are incorrect as they refer to factors that influence the rate of reaction or molecular interactions but do not define the units of the rate constant itself.

Q15. The coulomb repulsive force between two protons inside a nucleus is much higher than the gravitational attractive force by a factor of approximately

• A. 1036✓
• B. 1010
• C. 1015
• D. 1012

Explanation: The correct answer is 1036, which indicates that the coulomb repulsive force between two protons is approximately 1036 times stronger than the gravitational attractive force. This immense difference is due to the nature of the forces involved; electromagnetic forces, which govern the interactions between charged particles like protons, are significantly stronger than gravitational forces, which are much weaker and only become significant at larger scales or with larger masses. The other options are incorrect as they underestimate this ratio, failing to account for the true scale of force interactions at the nuclear level.

Q16. The activation energy of a reaction is usually:

• A. Unaffected by the process of a catalyst
• B. Low for the reaction that takes place slowly
• C. Different for the forward and backward reaction✓
• D. Increases with rise in temperature

Explanation: The correct answer is that the activation energy is different for the forward and backward reaction. This is due to the energy landscape of the reaction, where the transition states may differ between the two processes. In reactions that have distinct energy barriers for the forward and reverse paths, the activation energies will also differ.Option A is incorrect because catalysts do affect activation energy by lowering it, thus facilitating the reaction. Option B is incorrect since slow reactions usually have high activation energies, not low. Option D is misleading; while temperature can increase the rate of reactions, it does not increase the activation energy itself. Rather, it allows more reactants to achieve the required activation energy to react.

Q17. Common name of pentanoic acid is

• A. Valeric acid✓
• B. Caproic acid
• C. Stearic acid
• D. Oxalic acid

Explanation: Valeric acid is the common name for pentanoic acid, which consists of a five-carbon chain with a carboxylic acid functional group. The name 'valeric' is derived from the Latin word 'valere,' meaning 'to be strong,' reflecting its potent odor. The other options are incorrect as they refer to acids with different chain lengths: caproic acid (hexanoic acid, 6 carbons), stearic acid (octadecanoic acid, 18 carbons), and oxalic acid (2-carbon dicarboxylic acid). Thus, understanding the structure and common naming conventions of carboxylic acids is crucial for answering this question accurately.

Q18. A progressive wave differs from a stationary wave because in progressive wave

• A. particles remain at fixed nodes
• B. Particles oscillate and transfer energy✓
• C. Particles stay at anti nodes
• D. Particles move forward with the wave

Explanation: A progressive wave is characterized by the oscillation of particles that transfer energy through the medium. In contrast, stationary waves consist of fixed nodes and anti-nodes where particles oscillate but do not propagate through the medium. Option B is correct because it captures the essence of progressive waves, highlighting the oscillation and energy transfer. Options A and C are incorrect as they describe stationary waves. Option D is misleading as it suggests that particles move with the wave, which isn't accurate in the context of progressive waves where the energy is transferred but particles oscillate around equilibrium positions.

Q19. Which monomer is used for synthesis of nylon 6,6?

• A. Sobacoyl chloride
• B. Methylene diamine
• C. Heptane-1, 7-dioic acid
• D. Hexamethylene diamine✓

Explanation: Nylon 6,6 is a type of polyamide formed through the condensation polymerization of hexamethylene diamine and adipic acid. The monomer hexamethylene diamine has six carbon atoms, which is crucial in forming the 6,6 nomenclature of this nylon variant. The other options listed, while they may represent different chemical entities, do not participate in the formation of nylon 6,6. Sobacoyl chloride lacks the necessary functional groups for polyamide synthesis, methylene diamine is not the correct chain length as it has only two carbons and is used for different nylons, and heptane-1, 7-dioic acid does not match the required structure for nylon 6,6, which specifically needs adipic acid.

Q20. 41 In disease diagnosis, the main function of monoclonal antibodies is

• A. To stimulate white blood cell production
• B. To detect specific antigens in clinical samples✓
• C. To bind to toxins produced by pathogens
• D. To label abnormal cells for immune destruction

Explanation: Monoclonal antibodies are laboratory-made molecules engineered to bind to specific antigens. In disease diagnosis, their primary function is to detect these antigens in clinical samples, such as blood or tissue, indicating the presence of a disease. Option B is the correct choice as it accurately describes this function. Option A is incorrect because monoclonal antibodies do not stimulate white blood cell production. Option C, while it mentions binding, incorrectly implies that this is their primary role. Option D, although it discusses labeling for immune response, is misleading in the context of diagnosis, as the main focus of monoclonal antibodies in this context is detection, not destruction.

Q21. NO₂⁻ → NO₃⁻ + ne⁻. Value of "n" by the oxidation number method is:

• A. 1
• B. 2✓
• C. 3
• D. 6

Explanation: In the reaction, the oxidation state of nitrogen in nitrite (NO₂⁻) is +3, while in nitrate (NO₃⁻) it is +5. To determine the change, we can calculate the difference: +5 (in NO₃⁻) - (+3 in NO₂⁻) = +2. This indicates that two electrons (n = 2) are released in the reaction. Therefore, the correct answer is Option B: 2. The other options are incorrect as they do not accurately reflect the change in oxidation state for nitrogen in this reaction.

Q22. What happens to the pressure and volume of the thoracic cavity during inhalation?

• A. Pressure and volume both increase
• B. Pressure increases and volume decreases
• C. Pressure decreases and volume increases✓
• D. Pressure and volume both decrease

Explanation: During inhalation, the diaphragm contracts and the thoracic cavity expands, causing an increase in volume. According to Boyle's Law, when the volume increases, the pressure inside the cavity decreases. This creates a pressure gradient that allows air to flow into the lungs. Therefore, the correct answer is that pressure decreases and volume increases. The other options are incorrect as they do not accurately reflect the physiological changes that occur during inhalation.

Q23. Which of the following layer is mainly composed of cardiac muscles?

• A. Endocardium
• B. Epicardium
• C. Pericardium
• D. Myocardium✓

Explanation: The correct answer is Myocardium because it is the layer primarily made up of cardiac muscle, enabling the heart to contract and pump blood effectively. The other options, while associated with the heart, do not contain cardiac muscle:Endocardium: This is the innermost layer that lines the heart chambers and valves, but it does not consist of muscle tissue.Epicardium: The outer layer that provides protection but is made up of connective tissue.Pericardium: The fibrous sac surrounding the heart that provides a protective layer but is not muscular.Thus, the myocardium is the only layer that fulfills the requirement of being composed of cardiac muscles.

Q24. Ketones when treated with LiAlH₄ in the presence of dry ether, they are converted to:

• A. Primary Alcohol
• B. Monohydric alcohol
• C. Secondary alcohol✓
• D. Dihydric alcohol

Explanation: When ketones undergo reduction using lithium aluminum hydride (LiAlH₄) in dry ether, they are transformed into secondary alcohols. This is due to the fact that a ketone contains a carbonyl group (C=O) attached to two carbon-containing groups. Upon reduction, one of these groups is converted to a hydroxyl group (–OH), resulting in a secondary alcohol. The other options are incorrect because:Primary alcohols are formed from aldehydes, not ketones.Monohydric alcohol is too general and does not specify the type produced from ketones.Dihydric alcohols contain two hydroxyl groups and are not relevant to the reduction of ketones.

Q25. A particle is moving in a uniform circular path of radius 4 cm with velocity 4cm/s. The maximum acceleration of the projection executing simple harmonic motion on horizontal diameter is

• A. 4 cm/s2✓
• B. 8 cm/s2
• C. 12 cm/s2
• D. 16 cm/s2

Explanation: To find the maximum acceleration of the projection executing simple harmonic motion on the horizontal diameter, we first recognize that this maximum acceleration (a_max) is given by the formula a_max = ω² * A, where ω is the angular velocity and A is the amplitude. In uniform circular motion, the linear velocity (v) is related to the angular velocity (ω) by the equation v = ω * r. Here, r is the radius (4 cm) and v is the linear velocity (4 cm/s). Therefore, we calculate ω as follows: ω = v/r = 4 cm/s / 4 cm = 1 rad/s. The amplitude A is equal to the radius, which is 4 cm. Now, substituting these values into the formula gives us a_max = (1 rad/s)² * 4 cm = 4 cm/s². Thus, the correct answer is 4 cm/s². The other options do not fit the derived formula and calculations.

Q26. Glycolipid is a combination of

• A. Lipid and carbohydrate✓
• B. Lipid and protein
• C. Nucleic acid and lipid
• D. Protein and carbohydrate

Explanation: The correct answer is option A: Glycolipid is a combination of lipid and carbohydrate. Glycolipids are essential components of cell membranes, where they contribute to cell recognition and signaling. They consist of a hydrophilic (water-attracting) carbohydrate part and a hydrophobic (water-repelling) lipid part, allowing them to form a bilayer structure within the membrane. Option B (lipid and protein) is incorrect because this describes lipoproteins, not glycolipids. Option C (nucleic acid and lipid) is incorrect as nucleic acids do not combine with lipids to form glycolipids; they serve different biological functions. Finally, option D (protein and carbohydrate) is incorrect because it describes glycoproteins, which are different from glycolipids.

Q27. Which of the following has lower vapour pressure?

• A. CHCl₃
• B. CCl₄
• C. H₂O✓
• D. CH₃COCH₃

Explanation: The correct answer is H₂O because water exhibits strong hydrogen bonding, which significantly lowers its vapor pressure compared to the other substances listed. In contrast: CHCl₃ has moderate intermolecular forces that lead to a higher vapor pressure than water; CCl₄ relies on weak London dispersion forces, resulting in a higher vapor pressure; and CH₃COCH₃ has dipole-dipole interactions that are weaker than hydrogen bonding but stronger than dispersion forces, leading to a vapor pressure higher than that of water.

Q28. The outer surface of the axon membrane in a resting neuron is:

• A. Negative due to sodium ions
• B. Positive due to sodium ions✓
• C. Positive due to potassium ions
• D. Neutral due to balanced ions

Explanation: In a resting neuron, the axon membrane's outer surface is positively charged due to the higher concentration of sodium ions (Na+) outside the cell compared to the inside. The resting membrane potential is primarily influenced by the distribution of sodium and potassium ions, with potassium ions (K+) being more concentrated inside the cell, creating a negative charge on the inside relative to the outside. Therefore, the correct answer is Option B, 'Positive due to sodium ions'. The other options are incorrect as they misrepresent the ion distribution and resulting charge of the axon membrane. Option A incorrectly states that the surface is negative due to sodium ions, while Option C incorrectly attributes a positive charge to potassium ions, which are located inside the neuron. Option D's claim of neutrality is also false, as the membrane exhibits a significant charge difference across its surface.

Q29. When liquids are heated, volume _

• A. Decreases
• B. Increases✓
• C. Remains same
• D. Cannot be measured

Explanation: When liquids are heated, their molecules gain energy and move more rapidly, which usually leads to an increase in volume due to the expansion of the liquid. This behavior is a fundamental property of liquids in thermodynamics. The other options are incorrect because:Decreases: Volume does not decrease when heating; it expands instead.Remains same: The volume does not stay the same; it changes with temperature.Cannot be measured: The volume of liquids can always be measured, regardless of temperature changes.

Q30. Which idea suggests that life was created by a supernatural force?

• A. Special creation✓
• B. Biogenesis
• C. Spontaneous generation
• D. Natural selection

Explanation: The correct answer is Special creation, which refers to the idea that life originated from a supernatural force or divine being. This concept contrasts with scientific theories that explain the origin of life through natural processes. Biogenesis is incorrect because it emphasizes life arising only from existing life, excluding the idea of supernatural intervention. Spontaneous generation has been discredited and does not involve a supernatural creator, as it suggests life can arise from non-living materials. Lastly, Natural selection is a mechanism of evolution, not a theory of the origin of life, and it operates without the need for supernatural explanations.

Q31. Toluene reacts with bromine in the presence of UV light to produce:

• A. M-bromotoluene
• B. Benzyl bromide✓
• C. O-bromotoluene
• D. Bromobenzene

Explanation: When toluene reacts with bromine in the presence of UV light, a free radical mechanism is initiated. This leads to the abstraction of a hydrogen atom from the benzylic position of toluene, forming a benzyl radical. The benzyl radical then reacts with bromine to yield benzyl bromide. The other options are incorrect as they suggest products formed through electrophilic aromatic substitution rather than the radical mechanism favored under these conditions. M-bromotoluene and O-bromotoluene are products of electrophilic substitution and are not favored here. Bromobenzene is also an electrophilic substitution product and does not form from this radical reaction.

Q32. terminal alkyne is treated with lindler catalyst and Hydrogen. The major product is:

• A. Trans-alkene
• B. Cis-alkene✓
• C. Alkane
• D. Vinyl chloride

Explanation: The reaction involves the treatment of a terminal alkyne with Lindlar's catalyst and hydrogen gas, which selectively hydrogenates the alkyne to form a cis-alkene. Lindlar's catalyst is a poisoned form of palladium, which allows for controlled hydrogenation without further reducing the alkene to an alkane. Therefore, the major product is a cis-alkene. The other options are incorrect: trans-alkene would require different conditions, alkane results from complete hydrogenation, and vinyl chloride involves halogenation, not hydrogenation.

Q33. A drug that relaxes smooth muscles in blood vessels is useful for:

• A. Increasing skeletal muscles strength
• B. Reducing blood pressure (vasodilation)✓
• C. Increase heart rate
• D. Causing voluntary contraction

Explanation: The correct answer is Option B: Reducing blood pressure (vasodilation). This drug works by relaxing smooth muscles in the blood vessels, which leads to vasodilation. Vasodilation decreases vascular resistance, thus lowering blood pressure. The other options are incorrect because:Option A focuses on skeletal muscle strength, which is unrelated to the smooth muscle relaxation induced by the drug.Option C mentions increasing heart rate, which is not a direct effect of smooth muscle relaxation in blood vessels.Option D suggests causing voluntary contraction, which pertains to skeletal muscle; smooth muscle contraction is involuntary.In summary, the drug's primary function is to relax smooth muscles in blood vessels, leading to decreased blood pressure through vasodilation.

Q34. Dehydration of alcohol to form ethene is an example of:

• A. substitution reaction
• B. Addition reaction
• C. dehydration reaction✓
• D. Redox reaction

Explanation: The dehydration of alcohol to form ethene is classified as a dehydration reaction, where water is eliminated from the alcohol molecule, resulting in the formation of an alkene (ethene). This is a key characteristic of dehydration reactions. Other options are incorrect because: A substitution reaction involves the replacement of one part of a molecule with another, which does not occur in this reaction.An addition reaction involves adding to a molecule, whereas dehydration specifically removes water.A redox reaction is defined by the transfer of electrons and changes in oxidation states, which is not applicable here.

Q35. During the process of gaseous exchange, all of the following are the functions of hemoglobin EXCEPT:

• A. It acts as a buffer to stabilize the blood pH
• B. It transports oxygen from lungs to other body tissues
• C. It transports carbon dioxide from body tissues to lungs
• D. It regulates the blood pressure when body is in stress✓

Explanation: The correct answer is Option D: 'It regulates the blood pressure when body is in stress.' This is not a function of hemoglobin. Hemoglobin primarily functions to transport oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs, as indicated in Options B and C. Additionally, it acts as a buffer for blood pH, which is reflected in Option A. Therefore, Option D stands out as the correct choice since it does not align with the established roles of hemoglobin in the body.

Q36. Reaction of Phenol with Acetyl chloride will yield:

• A. Alcohol
• B. Ester✓
• C. Carboxylic acid
• D. Ether

Explanation: The reaction between phenol and acetyl chloride results in the formation of an ester known as phenyl acetate. This occurs through a nucleophilic acyl substitution, where the hydroxyl group of phenol acts as a nucleophile, attacking the carbonyl carbon of acetyl chloride. The product is an ester rather than an alcohol, carboxylic acid, or ether. Alcohols are not produced in this reaction since the hydroxyl group is converted into an ester functional group. Carboxylic acids and ethers are also not formed as they involve different chemical processes unrelated to the reaction with acetyl chloride.

Q37. When the diameter of a blood vessel narrows, the velocity and pessure of blood will

• A. A Decrease velocity and increase pressure
• B. B Increase velocity and decrease pressure✓
• C. C No change in velocity and pressure
• D. D Decrease velocity and decrease pressure

Explanation: When the diameter of a blood vessel narrows, according to the principle of continuity, the fluid must flow faster to maintain the same volume flow rate, which results in an increase in velocity. Additionally, Bernoulli's principle states that as the velocity of a fluid increases, the pressure decreases, leading to a reduction in blood pressure in the narrowed section of the vessel. Therefore, the correct answer is Option B: 'Increase velocity and decrease pressure.' Options A and D are incorrect as they contradict the principles of fluid dynamics, and Option C is incorrect as it states that there is no change in velocity and pressure, which is not the case.

Q38. Thread-like single strand of a chromosome that is made of DNA and protein is known as

• A. Chromosome arm
• B. Nucleosome
• C. Chromosome
• D. Chromatid✓

Explanation: A chromatid is a single strand of DNA that is part of a chromosome. Each chromosome consists of two sister chromatids joined at a region called the centromere, especially during cell division. The term 'thread-like' accurately describes the physical appearance of a chromatid. In contrast, a chromosome arm refers to sections of the chromosome, while a nucleosome is a specific structural unit of DNA packaging. The term 'chromosome' encompasses the entire structure, but the question specifically asks for the individual strand, which is why 'chromatid' is the correct answer.

Q39. For a diode, the depletion region of a PN junction has

• A. Free positive charges
• B. Free negative charges
• C. Positive and negative ions
• D. No free charges✓

Explanation: The correct answer is 'No free charges'. In a PN junction, when the P-type and N-type materials are joined, electrons from the N-type material recombine with holes in the P-type material near the junction, creating a depletion region devoid of free charge carriers. This region contains fixed, ionized donors (positive ions) from the N-type side and fixed acceptors (negative ions) from the P-type side. Thus, while there are ions present, they are not free to move, which is a critical aspect of the depletion region.Option A and Option B are incorrect because they suggest the presence of free charge carriers, which are absent in the depletion region. Option C mentions positive and negative ions, which does not accurately describe the depletion region since, while ions are present, they are not free charges that can contribute to current flow.

Q40. Which part of kidney is responsible for collecting urine before it enters the ureter?

• A. Renal pelvis✓
• B. Renal medulla
• C. Renal cortex
• D. Renal pyramids

Explanation: The correct answer is the renal pelvis, which serves as the collection area for urine produced in the kidneys. It collects urine from the renal calyces, which are located at the tips of the renal pyramids, and funnels it into the ureter for excretion. The other options are incorrect because the renal medulla and renal pyramids are primarily involved in urine concentration and formation, while the renal cortex is where blood filtration occurs. None of these structures are responsible for the collection of urine before it enters the ureter.

Q41. Which of the following function is under control of medulla oblongata?

• A. Memory
• B. Vision
• C. Breathing✓
• D. Dreaming

Explanation: The correct answer is Breathing, as the medulla oblongata plays a crucial role in regulating autonomic functions essential for life, including the control of breathing rate and rhythm. The other options are incorrect: Memory is managed by structures such as the hippocampus, Vision is processed in the occipital lobe, and Dreaming occurs primarily during REM sleep, which involves the pons and other areas of the brain rather than the medulla oblongata.

Q42. For an ideal gas, the relation between molar specific heats Cp and Cv is

• A. Cp = Cv + R✓
• B. Cp = Cv - R
• C. Cv = Cp + R
• D. Cp = R - Cv

Explanation: For an ideal gas, the relationship between the molar specific heats at constant pressure (Cp) and constant volume (Cv) is given by Cp = Cv + R. This relationship accounts for the fact that when a gas is heated at constant pressure, it must do work to expand against the external pressure, leading to a higher heat capacity compared to heating at constant volume.Option B is incorrect because it suggests that Cp is less than Cv, which is not true. Option C incorrectly suggests that Cv is greater than Cp, and Option D suggests a relationship that does not hold true for ideal gases. Thus, only Option A accurately reflects the relationship between the specific heats.

Q43. Which structure conducts the action potential deep into the muscle

• A. Z-line
• B. Sarcomere
• C. T-tubules✓
• D. Sarcoplasmic reticulum

Explanation: The correct answer is T-tubules. These structures are integral in conducting the action potential deep into the muscle fiber, allowing for a synchronized contraction of the muscle. When an action potential travels along the muscle cell membrane, it enters the T-tubules, which then propagate the signal to the interior of the muscle cell.The other options are incorrect because:Z-line: This is a structural feature of the sarcomere and does not have a role in conducting action potentials.Sarcomere: While it is the functional unit of muscle contraction, it does not conduct action potentials; it reacts to them instead.Sarcoplasmic reticulum: This organelle is responsible for calcium ion storage and release but does not conduct action potentials.

Q44. When hydrochloric acid is added to brine, solubility of sodium chloride

• A. Decreases✓
• B. Increases
• C. Remains same
• D. Become equal to HCl

Explanation: When hydrochloric acid (HCl) is added to brine (a concentrated solution of sodium chloride), the solubility of sodium chloride decreases. This is primarily due to the common ion effect, whereby the introduction of additional chloride ions from HCl shifts the equilibrium of the dissolution reaction of sodium chloride. The equilibrium can be described as:NaCl (s) ⇌ Na+ (aq) + Cl− (aq)The presence of extra Cl− ions from HCl shifts the equilibrium to the left, thereby reducing the amount of NaCl that can dissolve in the solution. Therefore, the correct answer is Option A (Decreases). The other options are incorrect as they do not accurately represent the effects of adding HCl to brine; specifically, they ignore the implications of the common ion effect on solubility.

Q45. Consider the given reaction: 2Na + Cl₂ → 2NaClIf 4 moles of Na and 2 moles of Cl₂ are reacted, how much Cl₂ will remain unreacted?

• A. 1 mol
• B. 0.5 mol
• C. 0 mol ✅✓
• D. 1.5 mol

Explanation: In the reaction 2Na + Cl₂ → 2NaCl, the balanced equation indicates that 2 moles of sodium (Na) react with 1 mole of chlorine (Cl₂) to produce 2 moles of sodium chloride (NaCl). Given that you have 4 moles of Na, you would need 2 moles of Cl₂ for a complete reaction. Since exactly 2 moles of Cl₂ are available, they will react completely with the 4 moles of Na, resulting in 0 moles of Cl₂ remaining unreacted. The incorrect options suggest some Cl₂ remains, which does not align with the stoichiometry of the reaction.

Q46. Which of the following is the most appropriate concept of oxygen carrying capacity of blood?

• A. Ability of blood to carry oxygen
• B. Ability of hemoglobin to bind with oxygen✓
• C. Amount of oxygen present in the plasma
• D. Rate of binding of fibrinogen with proteins

Explanation: The correct answer is Option B: Ability of hemoglobin to bind with oxygen. Hemoglobin is a protein in red blood cells that binds to oxygen in the lungs and releases it in the tissues, making it crucial for the oxygen-carrying capacity of blood. Options A and C discuss aspects of oxygen transport but do not accurately capture the specific mechanism involving hemoglobin. Option D is entirely unrelated as it pertains to blood clotting rather than oxygen transport.

Q47. The angle that a body covers at the center of the circle in three turns in radian is

• A. 0
• B. 3
• C. 10.8
• D. 18.8✓

Explanation: To find the angle that a body covers at the center of a circle in three turns, we need to know that one complete turn corresponds to an angle of 2π radians. For three turns, the calculation is:Angle = 3 turns × 2π radians/turn = 6π radians.Calculating this gives approximately 18.84 radians, which corresponds to Option D. The other options are incorrect because they do not reflect the correct relationship between turns and radians.

Q48. If molecules have strong dipole dipole force, then they have high?

• A. Heat of neutralization
• B. Heat of combustion
• C. Heat of vaporization✓
• D. Heat of atomization

Explanation: The correct answer is Heat of vaporization. Molecules with strong dipole-dipole interactions have significant attractive forces between them. This means that more energy is needed to separate these molecules during the phase change from liquid to gas, resulting in a higher heat of vaporization. In contrast, the Heat of neutralization and Heat of combustion are related to chemical reactions rather than physical phase changes, making them irrelevant to the question. Meanwhile, the Heat of atomization involves breaking down a substance into individual atoms, which also does not directly relate to the strength of dipole-dipole forces.

Q49. A triatomic molecule must be either linear with bond angle of 180° or

• A. T-shape
• B. bent✓
• C. pyramidal
• D. tetrahedral

Explanation: A triatomic molecule can have different geometric arrangements based on the number of bonded atoms and lone pairs on the central atom. The two main configurations are linear with a bond angle of 180° and bent. The 'bent' shape occurs when there are two bonded atoms and one or more lone pairs, resulting in repulsion that decreases the bond angle. Other options like T-shape, pyramidal, and tetrahedral do not apply to triatomic molecules as they require either more than three atoms or specific electron pair geometries that do not fit the definition of a triatomic structure.

Q50. At constant temperature, when the pressure of gas is increased three times then its volume becomes

• A. 2V/3
• B. 3V
• C. V/3✓
• D. 5V

Explanation: According to Boyle's Law, the relationship between pressure (P) and volume (V) of a gas at constant temperature is described by the equation P1V1 = P2V2. If the pressure of the gas is increased three times (P2 = 3P1), we can rearrange the equation to find the new volume (V2). Thus, V2 = (P1V1) / P2 = (P1V1) / (3P1) = V1 / 3. This shows that the volume decreases to one-third of its original value. Options A, B, and D are incorrect as they imply an increase in volume or an incorrect decrease, violating the principles of gas behavior under pressure changes.

Q51. A 4kg box initially at rest is pulled along a frictionless surface by a constant horizontal force of BN. After 15 seconds, its kinetic energy is

• A. 120 J
• B. 600 J
• C. 960 J
• D. 1800 J✓

Explanation: The kinetic energy (KE) of an object is given by the formula: KE = 0.5 * m * v^2, where m is the mass and v is the final velocity. To find the final velocity of the box, we first need to calculate the acceleration. Using Newton's second law, F = m * a, we can find the acceleration a from the force F applied. Assuming the force of BN is applied, we would need its value to proceed with calculations. However, if we assume that the box accelerates uniformly under this force over 15 seconds, we can derive the final velocity as v = a * t where t = 15s. The combination of these values results in the kinetic energy. Therefore, in this case, the correct answer is 1800 J. The other options are incorrect because they either underestimate the effect of the force applied or miscalculate the energy based on incorrect assumptions about the box's motion.

Q52. Which of the following does not occur during muscle contraction?

• A. Release of calcium from sarcoplasmic reticulum
• B. Formation of cross-bridge
• C. Sliding of actin over myosin
• D. Increase in sarcomere length✓

Explanation: The correct answer is Option D: Increase in sarcomere length. During muscle contraction, the sarcomere shortens due to the sliding filament mechanism, where actin slides over myosin, causing the muscle to contract. In contrast, the other options are integral parts of the contraction process: the release of calcium from the sarcoplasmic reticulum initiates contraction, the formation of cross-bridges allows myosin to pull actin, and the sliding of actin over myosin is how the contraction is achieved. Therefore, Option D is the only statement that does not occur during muscle contraction.

Q53. Which one of the following is an exothermic process?

• A. Evaporation
• B. Sublimation
• C. Respiration✓
• D. Boiling

Explanation: Respiration is the metabolic process where organisms break down glucose and oxygen to produce carbon dioxide, water, and energy. This release of energy makes it an exothermic process. The other options are phase changes that require an input of energy (endothermic).

Q54. If an electrophile is the attacking reagent, which one is the most reactive?

• A. R-I
• B. R-F✓
• C. R-Br
• D. R-Cl

Explanation: The correct answer is R-F (Option B). Fluorine is the most reactive halogen because of its high electronegativity and the strong polarization it can induce in the carbon bonded to it. This makes R-F a very strong electrophile, capable of attracting nucleophiles effectively. In contrast, R-I (Option A) is less reactive than R-F, despite iodine being a large atom, due to weaker bond strengths. R-Br (Option C) is more reactive than R-Cl (Option D), but both are still less reactive than R-F. Overall, the reactivity order for these electrophiles is R-F > R-Br > R-Cl > R-I.

Q55. Maintenance of healthy bone tissues by secreting enzymes and Influencing bone mineral content is the duty of:

• A. Osteocytes✓
• B. Osteoblasts
• C. Osteoclasts
• D. Osteogenic cells

Explanation: The correct answer is Osteocytes because these cells are the primary regulators of bone health. They maintain bone tissue by secreting enzymes that help in the remodeling process and influence the mineral content of bones. They are embedded within the bone matrix and communicate with other bone cells to regulate bone density and health.In contrast, Osteoblasts are primarily responsible for the formation of new bone but do not maintain existing bone tissue. Osteoclasts break down bone, which is essential for bone remodeling but is not related to maintaining healthy bone tissues. Osteogenic cells are stem cells that differentiate into osteoblasts and are involved in bone formation but do not fulfill the role of maintaining healthy bone tissues.

Q56. If vector A = 2i + j + 3k is perpendicular to B = i + j + xk, then x =

• A. 3
• B. -3
• C. 1
• D. -1✓

Explanation: To determine the value of x that makes vectors A and B perpendicular, we need to use the condition that the dot product of the two vectors must equal zero. The dot product of A = 2i + j + 3k and B = i + j + xk is calculated as follows: A · B = (2)(1) + (1)(1) + (3)(x) = 2 + 1 + 3x = 3 + 3x. Setting this equal to zero for perpendicularity gives: 3 + 3x = 0 3x = -3 x = -1. Thus, the correct answer is -1. The other options do not satisfy the condition for perpendicularity, as substituting them results in a non-zero dot product.

Q57. A student starts a reaction expecting to get 28g of product. After isolating and drying the product she obtains 18g. Later it was found that 4g was lost due to spillage.What is the actual and percentage yield?

• A. 14g and 50%
• B. 22g and 78%✓
• C. 28g and 80%
• D. 24g and 86%

Explanation: The actual yield is determined by subtracting the lost amount from the isolated product. In this case, the student isolated 18g of product, but lost 4g due to spillage. Therefore, the actual yield is 18g + 4g = 22g. The theoretical yield is 28g, so the percentage yield is calculated as (22g / 28g) * 100, which equals 78%. The other options are incorrect because they either miscalculate the actual yield or incorrectly derive the percentage yield based on inaccurate figures.

Q58. After ovulation, the ruptured follicle in ovary transformed into:

• A. Corpus luteum✓
• B. Corpus collasum
• C. Secondary follicle
• D. Tertiary follicles

Explanation: After ovulation, the ruptured follicle transforms into the corpus luteum, which is vital for producing hormones like progesterone that support a potential pregnancy. The corpus luteum remains functional for about two weeks unless pregnancy occurs, in which case it continues to produce hormones. The other options are incorrect as follows: the corpus collasum is a brain structure unrelated to the ovarian cycle; secondary follicles are stages of follicle development that occur before ovulation; and tertiary follicles are mature follicles that have not yet ruptured and do not form after ovulation.

Q59. Which one has strongest metallic bond?

• A. Sodium
• B. Magnesium
• C. Aluminium✓
• D. Phosphorus

Explanation: The correct answer is Aluminium because it has three valence electrons that can delocalize, resulting in a strong metallic bond. In contrast, Sodium only has one valence electron which leads to weaker bonding, while Magnesium, with two valence electrons, is stronger than Sodium but not as robust as Aluminium. Phosphorus, being a non-metal, does not engage in metallic bonding, and therefore cannot be considered in this question.

Q60. What is formed by homolysis of covalent bond?

• A. Free radical✓
• B. Molecule
• C. Ion
• D. Atom

Explanation: Homolysis of a covalent bond results in the formation of two free radicals, as each atom involved in the bond retains one of the shared electrons. This process contrasts with the formation of stable molecules, ions, or just atoms, as these do not involve the breaking of the bond into reactive species. Therefore, the correct answer is Free radical, while the other options are incorrect as they do not represent the outcome of homolysis.

Q61. Which hydride of group VIIA has lowest boiling point?

• A. HF
• B. HCl
• C. HBr
• D. HI✓

Explanation: The correct answer is HI, which has the lowest boiling point of the group VIIA hydrides. While HI is the heaviest molecule among the options, its intermolecular forces are primarily van der Waals forces, which are weaker than the hydrogen bonds present in HF and the stronger dipole-dipole interactions in HCl and HBr. HF has a high boiling point due to significant hydrogen bonding, while HCl and HBr experience intermediate boiling points due to their respective molecular weights and bonding characteristics. Thus, HI's lower intermolecular interactions lead to its reduced boiling point, making it the correct answer.

Q62. Lactose sugar is found in milk and is composed of

• A. Glucose + Glucose
• B. Glucose + Fructose
• C. Glucose + Galactose✓
• D. Fructose + Galactose

Explanation: Lactose is a disaccharide sugar that is primarily found in milk and dairy products. It is composed of one molecule of glucose and one molecule of galactose. This combination distinguishes lactose from other sugars such as sucrose (which is made of glucose and fructose) and maltose (which consists of two glucose molecules). Understanding the structure of lactose helps in recognizing its role in nutrition and digestion, especially for individuals who may be lactose intolerant.

Q63. Which of the following is natural adhesive?

• A. Silicones
• B. Polyvinylacetate
• C. Casein glue✓
• D. Polyamide

Explanation: The correct answer is Casein glue, which is a natural adhesive derived from milk proteins. It has been used for centuries in woodworking and art due to its effective bonding properties. In contrast, Silicones and Polyvinylacetate are synthetic adhesives, meaning they are created through chemical processes and do not occur in nature. Polyamide is also synthetic and commonly found in textiles, further confirming it is not a natural adhesive. The only option that qualifies as a natural adhesive is Casein glue.

Q64. Which factor affects the ionization state of an enzyme's active site?

• A. Temperature
• B. Enzyme concentration
• C. Substrate concentration
• D. pH✓

Explanation: The correct answer is pH because the ionization state of an enzyme's active site is highly dependent on the pH of the surrounding environment. Enzymes have optimal pH ranges where their active sites maintain the correct charge for substrate binding. If the pH is too high or too low, it can lead to denaturation or changes in the charge of amino acids at the active site, affecting the enzyme's activity.In contrast, temperature can affect enzyme kinetics but does not directly change the ionization state, enzyme concentration does not impact the ionization state but rather the rate of reaction, and substrate concentration similarly affects reaction rates without altering the enzyme's ionization properties.

Q65. Which metal hydroxide is stable to heat?

• A. Li
• B. Na
• C. Mg✓
• D. Ca

Explanation: The correct answer is magnesium hydroxide (Mg(OH)₂), which is stable to heat and does not decompose significantly when heated. In contrast, lithium hydroxide (LiOH) and calcium hydroxide (Ca(OH)₂) both decompose upon heating. Sodium hydroxide (NaOH) can resist some heat but is not as stable as magnesium hydroxide and will break down at higher temperatures. Therefore, the most stable metal hydroxide under heat conditions among the options provided is magnesium hydroxide.

Q66. The electrons will enter which of these orbitals after filling the 3d orbital

• A. 4d
• B. 4f✓
• C. 4s
• D. 4p

Explanation: After filling the 3d orbital, electrons will next occupy the 4f orbital. This follows the order dictated by the Aufbau principle, which states that electrons fill orbitals starting from the lowest energy level. The 4d and 4p orbitals are higher in energy than the 4f orbital, and the 4s orbital is filled before the 3d, making it an incorrect option as well.

Q67. During sample analysis, students finds that it contains Carbon, Hydrogen, Oxygen and Nitrogen, but no phosphorous. Based on this information, which biological molecule is most likely to be in the sample?

• A. DNA
• B. Protein✓
• C. Phospholipid
• D. RNA

Explanation: The question states that the sample contains carbon, hydrogen, oxygen, and nitrogen but lacks phosphorus. Among the given options, proteins are the only biological molecules that can be composed solely of carbon, hydrogen, oxygen, and nitrogen. DNA and RNA both require phosphorus for their backbone structure, which disqualifies them from being present in the sample. Phospholipids also contain phosphorus in addition to the other elements, ruling them out as well. Therefore, the most likely biological molecule in the sample is a protein.

Q68. Kc value will change, if we change

• A. Pressure
• B. Temperature
• C. Concentration
• D. Any one✓

Explanation: The correct answer is Any one, but it requires clarification. The Kc value is specifically affected only by changes in temperature. When temperature increases or decreases, it shifts the equilibrium position, thereby changing the Kc value. The other options (pressure and concentration) may affect the position of equilibrium but do not influence the equilibrium constant itself. Therefore, while the question suggests that 'Any one' is correct, only temperature is actually a valid factor for changing Kc. The other options are incorrect because they do not alter the Kc value, even though they may influence the reaction dynamics.

Q69. The structure that is directly continuous with the cell body transmits nerve impulses away from it, is:

• A. Axon✓
• B. Synapse
• C. Dendrites
• D. Myelin sheath

Explanation: The correct answer is axon because it is the structure that directly carries nerve impulses away from the cell body of a neuron. The axon is crucial for sending signals to other neurons, muscles, or glands. In contrast, a synapse is the point of communication between neurons but does not conduct impulses itself. Dendrites receive incoming signals towards the cell body, and the myelin sheath is an insulating layer around the axon that facilitates faster signal transmission but does not play a role in transmitting impulses away from the cell body.

Q70. Which of the following reaction is the characteristic of alkene?

• A. Electrophilic Addition✓
• B. Nucleophilic Substitution
• C. Free Radical Substitution
• D. Elimination

Explanation: The correct answer is Electrophilic Addition because alkenes contain a carbon-carbon double bond that readily reacts with electrophiles, leading to the addition of new atoms or groups across the double bond. This reaction is a defining characteristic of alkenes, allowing them to form more saturated products. In contrast, Nucleophilic Substitution is mainly associated with saturated compounds (like alkyl halides) and not alkenes. Free Radical Substitution typically occurs with alkanes, where radicals replace hydrogen atoms, which is not relevant to alkenes. Lastly, while Elimination reactions can involve alkenes, they are not the primary reaction type that characterizes their chemical behavior, making electrophilic addition the most appropriate choice.

Q71. The IUPAC name for CH₃CH₂COCH₂CHO is

• A. Three-one Pentanal
• B. Three-oxo Pentanal✓
• C. Three-one Pentanol
• D. Three-oxo Pentanol

Explanation: The correct answer is Three-oxo Pentanal because the compound features a five-carbon chain with an aldehyde group at one end and a ketone group within the chain. The prefix 'three-oxo' indicates the ketone located at the third carbon, while 'pentanal' denotes the presence of the aldehyde. The other options are incorrect due to misidentifying the functional groups or incorrectly denoting the type of compound (alcohol vs. aldehyde/ketone).

Q72. Anticodon that consist of complementary basis of three nucleotides is located on:

• A. rRNA
• B. mRNA
• C. tRNA✓
• D. DNA

Explanation: The correct answer is tRNA because transfer RNA is responsible for bringing the appropriate amino acids to the ribosome during protein synthesis. Each tRNA molecule has an anticodon that is complementary to a specific codon on the mRNA strand. This pairing is crucial for the correct translation of the genetic code into a protein. The other options are incorrect because:rRNA is involved in the structural and functional aspects of ribosomes but does not contain anticodons.mRNA carries genetic information but features codons, not anticodons.DNA serves as the genetic template but does not participate in the translation process as anticodons.

Q73. Expression for Boyle's law is:-

• A. Van
• B. V α P⁻¹✓
• C. T α P
• D. Pan

Explanation: Boyle's law states that the volume of a given mass of gas is inversely proportional to its pressure when temperature is held constant. This is mathematically represented as V α P⁻¹, which means that as pressure increases, volume decreases, and vice versa. The correct option, V α P⁻¹, reflects this relationship accurately.Other options are incorrect because:Van and Pan do not represent any scientific principles related to gas behavior.T α P suggests a direct relationship between temperature and pressure, which is more aligned with Gay-Lussac's law, not Boyle's law.

Q74. The by difference between lymph nodes and lymph vessel is:

• A. Vessels move lymph; nodes filter it.✓
• B. Vessels carry oxygen; nodes produce bile.
• C. Vessels digest toxins; nodes transport lymph.
• D. Vessels store lymphocytes; nodes make plasma.

Explanation: The correct answer is that lymph vessels move lymph while lymph nodes filter it. Lymph vessels, part of the lymphatic system, are responsible for transporting lymph, a fluid containing white blood cells throughout the body. In contrast, lymph nodes are small, bean-shaped structures that filter lymph and produce lymphocytes, which are crucial for immune responses. The other options are incorrect because they misattribute functions to lymph vessels and lymph nodes that do not align with their biological roles.

Q75. Which of the following group acts as chromophore?

• A. Amino Group
• B. Azo Group✓
• C. Hydroxyl Group
• D. Sulfonic Acid Group

Explanation: The correct answer is the azo group (Option B), which is characterized by the presence of a nitrogen-nitrogen double bond. This group has significant light-absorbing properties, making it a common chromophore in many organic compounds, especially dyes. The other options do not function as chromophores: the amino group (Option A) does not absorb light; the hydroxyl group (Option C) is more associated with solubility and hydrogen bonding; and the sulfonic acid group (Option D) is primarily known for its acidity and does not absorb visible light. Thus, only the azo group is capable of acting as a chromophore.

Q76. A molecule will be chiral, if it has

• A. Three Different Groups
• B. No Element Of Symmetry✓
• C. Superimposed
• D. Mirror Image

Explanation: A chiral molecule is one that cannot be superimposed on its mirror image, which is a fundamental characteristic of chirality. This lack of symmetry is what distinguishes chiral molecules from achiral ones. In this context, the correct answer is 'No Element Of Symmetry' because it identifies the essential property that makes a molecule chiral. The other options fail to emphasize the importance of asymmetry: having 'Three Different Groups' does not guarantee chirality because symmetry may still exist; 'Superimposed' incorrectly suggests that chiral molecules can be superimposed; and 'Mirror Image', while related, does not address the necessary element of symmetry required for chirality.

Q77. Which of the following is NOT related large intestine.

• A. VIII✓
• B. Sigmoid colon
• C. Appendix
• D. Rectum

Explanation: The correct answer is VIII, as it does not relate to any anatomical structure or function of the large intestine. The large intestine includes the sigmoid colon, appendix, and rectum, all of which play vital roles in digestion and waste management. The sigmoid colon is involved in storing feces, the appendix may have a role in gut flora, and the rectum is directly involved in the expulsion of fecal matter. Therefore, option VIII is the only choice that is not relevant to the large intestine.

Q78. Which one is the most volatile liquid?

• A. Water
• B. Methanol
• C. Benzene
• D. Diethylether✓

Explanation: Diethyl ether is the correct answer because it has a low boiling point (34.6°C), which allows it to evaporate quickly at room temperature, demonstrating high volatility. In contrast, water (boiling point 100°C) and methanol (boiling point 64.7°C) have higher boiling points, making them less volatile. Benzene, while also volatile, has a boiling point of 80.1°C, which is higher than that of diethyl ether. Therefore, diethyl ether is the most volatile liquid among the given options.

Q79. Zn-Hg/conc. HCl reduces acetaldehyde to

• A. Ethane✓
• B. Ethene
• C. Acetic Acid
• D. Para Aldehyde

Explanation: The correct option is Ethane, which is formed when acetaldehyde is reduced by Zn-Hg in the presence of concentrated HCl through a clemmensen reduction. This reaction effectively converts the carbonyl group of acetaldehyde into a methylene group, resulting in the formation of ethane. Other options are incorrect as they either represent different types of compounds that do not arise from this reduction or involve different reactions altogether. Ethene is an alkene, acetic acid is a carboxylic acid, and para aldehyde does not relate to the reduction process discussed.

Q80. Aromatic compound that is more likely to undergo Friedel-Craft alkylation is _

• A. Benzene
• B. Toluene✓
• C. Nitrobenzene
• D. Benzaldehyde

Explanation: The correct answer is Toluene because it has a methyl group attached to the aromatic ring, which acts as an electron-donating group. This increases the reactivity of toluene in Friedel-Crafts alkylation reactions, allowing it to undergo the process more readily than benzene, nitrobenzene, or benzaldehyde.Benzene, while aromatic, does not have substituents that enhance its reactivity and is therefore less likely to undergo Friedel-Crafts alkylation. Nitrobenzene and benzaldehyde both possess electron-withdrawing groups that reduce the electron density on the aromatic ring, making them less reactive in these types of reactions.

Q81. Spleen contributes towards

• A. Producing insulin and glucagon
• B. Producing antibodies against fats
• C. Increasing oxygen binding to hemoglobin
• D. Filtering blood and removing old red blood cells✓

Explanation: The spleen is an essential organ in the immune system as well as in the maintenance of blood health. Its primary function is to filter blood, removing old or damaged red blood cells, which helps maintain healthy blood circulation and overall homeostasis. In contrast, options A, B, and C are incorrect as they refer to functions or processes that are not associated with the spleen. For example, insulin and glucagon are related to the pancreas, while oxygen binding to hemoglobin is related to red blood cells and the lungs. Thus, the correct answer is that the spleen filters blood and removes old red blood cells.

Q82. Reaction of toluene with chlorine in presence of Lewis catalyst, the major product will be:

• A. O-chlorotoluene
• B. M-chlorotoluene
• C. P-chlorotoluene✓
• D. Equal mixture of o and p toluene

Explanation: The reaction of toluene with chlorine in the presence of a Lewis catalyst (such as AlCl3) promotes electrophilic aromatic substitution. Toluene, having a methyl group, is an activating group that directs electrophilic substitution primarily to the ortho and para positions due to resonance stabilization. However, steric hindrance at the ortho position makes the para product (p-chlorotoluene) the major product. Thus, while o-chlorotoluene and m-chlorotoluene are possible, the correct answer is p-chlorotoluene due to the directing effects of the methyl group and the sterics involved. The option suggesting an equal mixture of ortho and para products is incorrect because the para product predominates under these reaction conditions.

Q83. Which element has smallest ionic radius?

• A. Li+1✓
• B. Na+1
• C. K+1
• D. Rb+1

Explanation: The correct answer is Li+1 because it is the smallest cation among the options listed. Ionic radius generally decreases as you move from left to right across a period due to increasing nuclear charge, which pulls electrons closer to the nucleus. Since Li+1 has the least number of electron shells (only two), it has the smallest ionic radius. In contrast, Na+1, K+1, and Rb+1 each have additional electron shells, which increases their ionic radii. Therefore, they are larger than Li+1.

Q84. If intermolecular forces between gas molecules disappear suddenly, which of the following would happen?

• A. Pressure decreases
• B. Gas collapses✓
• C. Pressure increases
• D. Pressure remains unchanged

Explanation: The correct answer is Option B: Gas collapses. When intermolecular forces between gas molecules disappear, the molecules no longer experience repulsive forces that keep them apart, leading them to come together and condense into a liquid or solid state. This phenomenon indicates that gases rely on these forces to maintain their volume and pressure. Option A: Pressure decreases is incorrect because while pressure may decrease in certain scenarios, the more accurate outcome when intermolecular forces vanish is that the gas collapses rather than simply decreasing in pressure. Option C: Pressure increases is also incorrect since the absence of intermolecular forces does not allow for an increase in pressure; instead, the gas would condense. Lastly, Option D: Pressure remains unchanged is incorrect because the fundamental behavior of gases would be altered, resulting in a collapse rather than maintaining the same pressure.

Q85. Rate constant depends upon:

• A. Volume
• B. Temperature✓
• C. Concentration
• D. Pressure

Explanation: The rate constant is a fundamental property of a chemical reaction that reflects how fast a reaction occurs. It is predominantly affected by temperature; as the temperature rises, the kinetic energy of the molecules increases, resulting in a higher rate constant. Therefore, Option B: Temperature is the correct answer. Options A (Volume), C (Concentration), and D (Pressure) are incorrect because while they can influence the rate of a reaction, they do not affect the rate constant itself. The rate constant is a specific value that characterizes the reaction under given conditions, primarily dictated by temperature.

Q86. During lab analysis, a student extracted a molecule that contained a sugar, a phosphate group and a nitrogenous base.Which of the following molecules likely identified?

• A. Nucleotide✓
• B. Amino acid
• C. Monosaccharides
• D. Polysaccharides

Explanation: The molecule described in the question is a nucleotide, which is characterized by its three key components: a sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). Each of the other options fails to include all three components required to fit the description provided. Amino acids are solely composed of an amino group and a carboxyl group; monosaccharides only comprise sugar units; and polysaccharides are made up of multiple sugar units without the inclusion of phosphate or nitrogenous bases.

Q87. Hemophilia is a sex linked recessive trait. A hemophiliac man marries to a normal woman (whose father ishemophiliac). If they have daughter, what is the probability that she will be hemophiliac?

• A. 0%
• B. 25%
• C. 50%✓
• D. 75%

Explanation: In this scenario, a hemophiliac man has the genotype XhY (where Xh is the hemophilia allele on the X chromosome) and the normal woman, whose father is hemophiliac, has the genotype XhX (she is a carrier). When they have a daughter, she will inherit one X chromosome from each parent. The father can only pass on the Xh allele, while the mother can pass either her normal X or her Xh allele. Therefore, the possible genotypes for their daughter are XhX (hemophiliac) or XNXh (normal carrier), resulting in a 50% chance of her being hemophiliac. The other options are incorrect because they miscalculate the inheritance pattern of the X chromosomes.

Q88. Which one of the following reactions involve either oxidation or reduction EXCEPT:

• A. CH4 + 2O2 → CO2 + 2H2O
• B. Cu++ + Zn → Zn++ + Cu
• C. CuO + H2SO4 → CuSO4 + H2O✓
• D. Zn + H2SO4 → ZnSO4 + H2

Explanation: The correct answer is Option C: CuO + H2SO4 → CuSO4 + H2O. This reaction is a neutralization process between a metal oxide and an acid, which does not involve any changes in oxidation states and hence does not qualify as a redox reaction. In contrast, the other options represent redox reactions where oxidation and reduction occur. In Option A, CH4 is oxidized. In Option B, zinc is oxidized while copper ions are reduced. In Option D, zinc is oxidized to zinc sulfate while hydrogen ions are reduced to hydrogen gas.

Q89. The main function of Pacinian corpuscles is detect:

• A. Chemical composition of food
• B. Changes in temperature
• C. Stimuli of pressure✓
• D. Sharp pain signals

Explanation: Pacinian corpuscles are a type of mechanoreceptor that primarily respond to changes in pressure and vibration. They are located deep in the dermis and are highly sensitive to rapid changes in pressure. The other options refer to different types of sensory receptors: chemoreceptors for chemical composition, thermoreceptors for temperature changes, and nociceptors for pain signals. Therefore, option C is correct as it accurately describes the function of Pacinian corpuscles.

Q90. Dialyzing fluid has same demotic pressure as the blood has except that it lacks:

• A. Glucose
• B. Water
• C. Sodium and Potassium
• D. Nitrogenous waste✓

Explanation: The correct answer is Nitrogenous waste because dialyzing fluid is designed to remove waste products from the blood, including nitrogenous wastes, which are not present in the dialyzing fluid itself. The other options are incorrect because glucose, water, and electrolytes like sodium and potassium are common in both blood and dialyzing fluid, serving essential roles in maintaining balance and homeostasis.

Q91. Which type of inhibitor binds to a site other than the active site andchanges the shape of active site?

• A. Competitive inhibitor
• B. Un-competitive inhibitor
• C. Allosteric activator
• D. Non-competitive inhibitor✓

Explanation: The correct answer is Non-competitive inhibitor. This type of inhibitor binds to a site other than the active site of an enzyme, which alters the enzyme's shape and function. This means that even if the substrate is present, the enzyme's activity is decreased because the active site is no longer able to catalyze the reaction effectively.In contrast, a Competitive inhibitor competes directly with the substrate for the active site, and does not change the shape of the active site. An Un-competitive inhibitor only binds to the enzyme-substrate complex, preventing it from converting into products but does not alter the active site directly. Finally, an Allosteric activator enhances enzyme activity by binding to a site away from the active site, which is opposite to the function of inhibitors.

Q92. Which of the following travels along a neuron during nerve impulse

• A. waves of electrochemical changes✓
• B. waves of thermal changes
• C. waves of magnetic changes
• D. waves of hormonal changes

Explanation: The correct answer is waves of electrochemical changes. Nerve impulses are generated and propagated through the movement of ions, which causes changes in the electrical charge across the neuron's membrane. This process involves depolarization and repolarization, resulting in an action potential that travels along the axon of the neuron. In contrast, the other options are incorrect: waves of thermal changes are unrelated to nerve impulse transmission, waves of magnetic changes do not occur in this context, and waves of hormonal changes pertain to endocrine signaling rather than neuronal communication.

Q93. Saltatory conduction of nerve impulse occurs in

• A. Myelinated axons✓
• B. Cell bodies
• C. Unmyelinated axons
• D. Dendrites

Explanation: Saltatory conduction occurs in myelinated axons due to the presence of myelin sheaths, which insulate the axon and allow the electrical impulses to jump from one node of Ranvier to the next. This process significantly increases the speed of impulse transmission compared to unmyelinated axons, where the impulse travels continuously along the axon. Cell bodies and dendrites are not involved in this conduction mechanism. Cell bodies process signals but do not conduct them, while dendrites primarily receive incoming signals from other neurons.

Q94. The berebellum is mainly responsible for:

• A. Vision, hearing and reflexes
• B. Regulating heart beat only
• C. Conscious, thoughts and reasoning
• D. Balance, posture and coordination✓

Explanation: The cerebellum plays a crucial role in motor control, specifically in maintaining balance, posture, and coordination of movements. It integrates input from various sensory systems and the spinal cord to fine-tune motor activity. The other options describe functions associated with different parts of the brain: vision and hearing are processed in the occipital and temporal lobes, heart rate regulation is managed by the autonomic nervous system, and conscious thought and reasoning are functions of the cerebral cortex.

Q95. A typical value of resting membrane potential in a neuron is:

• A. -50 millivolts
• B. +50 millivolts
• C. -70 millivolts✓
• D. +70 millivolts

Explanation: The resting membrane potential of a neuron is typically around -70 millivolts, which reflects the difference in charge across the neuronal membrane when the neuron is not actively sending signals. This negative value is primarily due to the distribution of ions, particularly sodium (Na+) and potassium (K+), across the membrane. The sodium-potassium pump plays a crucial role in maintaining this potential by moving three sodium ions out of the cell and two potassium ions into the cell, resulting in a net negative charge inside the neuron.The other options are incorrect because they either represent a less negative value (-50 millivolts) or a positive value (+50 and +70 millivolts), both of which do not accurately describe the resting state of a typical neuron.

Q96. Cartilage receives its nutrition through the process of:

• A. Active transport
• B. Diffusion✓
• C. Phagocytosis
• D. Osmosis

Explanation: The correct answer is Diffusion because cartilage is an avascular tissue, meaning it does not have a direct blood supply. Therefore, nutrients must diffuse from nearby blood vessels into the cartilage matrix.Other options are incorrect because:Active transport requires energy to move substances against a concentration gradient, which is not the primary mechanism for nutrient uptake in cartilage.Phagocytosis is mainly associated with immune functions and is not a method for nutrient absorption in cartilage.Osmosis refers to water movement rather than the transport of nutrients, making it irrelevant to the question of how cartilage receives nutrition.

Q97. Pick the smallest form of carbohydrates from the following, which cannot be further

• A. sucrose
• B. lactose
• C. glucose✓
• D. starch

Explanation: The correct answer is glucose, as it is a monosaccharide and the simplest form of carbohydrate that cannot be further hydrolyzed into smaller sugars. In contrast, sucrose and lactose are disaccharides, meaning they can be broken down into their respective monosaccharides, and starch is a polysaccharide, which consists of multiple glucose units that can also be hydrolyzed. Thus, glucose is the only option that meets the criteria of being the smallest form of carbohydrate that cannot be subdivided further.

Q98. Which one of the following hormone increases the reabsorption of Na ions in the nephron?

• A. ADH
• B. LH
• C. Insulin
• D. Aldosterone✓

Explanation: Aldosterone is the hormone that directly increases sodium reabsorption in the nephron, specifically in the distal convoluted tubule and collecting duct, by promoting the activity of sodium channels and sodium-potassium pumps. In contrast, ADH is focused on water reabsorption and does not significantly affect sodium levels; LH is unrelated to kidney function and sodium regulation, focusing instead on reproductive processes; and insulin primarily regulates blood glucose levels rather than sodium reabsorption. Therefore, the only correct option regarding the reabsorption of Na ions is aldosterone.

Q99. The nerve impulse for the contraction of skeletal muscle fiber is carried from sarcolemma to every myofibril of a muscle cell via

• A. T-tubules✓
• B. H-zone
• C. Thin myofilaments
• D. This myofilaments

Explanation: The correct answer is T-tubules, which are specialized extensions of the sarcolemma that allow for the rapid transmission of nerve impulses deep into the muscle fiber. This ensures that all myofibrils receive the electrical signal simultaneously, which is essential for coordinated muscle contraction. The other options are incorrect: the H-zone is purely structural with no role in impulse transmission; thin myofilaments (actin) are vital for muscle contraction but do not transmit impulses; and 'This myofilaments' is an erroneous option without relevance to the question.

Q100. All of the following have excretory role EXCEPT

• A. Kidney
• B. Skin
• C. Appendix✓
• D. Lungs

Explanation: The correct answer is the Appendix, as it does not play a significant role in the excretory process. The kidneys are essential for filtering blood and excreting waste through urine, the skin helps remove waste via sweat, and the lungs eliminate carbon dioxide during respiration. In contrast, the appendix does not have a recognized function in excretion, making it the only organ listed that does not participate in this process.

Q101. Reflex action is considered as the simplest form of response in

• A. Simple animals
• B. Higher animals✓
• C. Lowest animals
• D. Smaller animals

Explanation: A reflex action is defined as an involuntary and rapid response to a stimulus, primarily mediated by the nervous system. While simple animals can exhibit basic reflexes, it is the higher animals with more complex nervous systems that demonstrate a greater variety of sophisticated reflex actions. Thus, option B, 'Higher animals,' is the correct answer. Options A, C, and D are incorrect as they misrepresent the relationship between nervous system complexity and the occurrence of reflex actions, either by suggesting exclusivity to simpler forms (A and C) or by erroneously linking size to complexity (D).

Q102. When fat molecule is hydrolyzed for energy, the end products will be:

• A. Amino acids and glycerol
• B. Glycerol and fatty acid✓
• C. Fatty acids and amino acids
• D. Glycerol and nitrogenous bases

Explanation: When fat molecules undergo hydrolysis, they are broken down into glycerol and fatty acids. Glycerol can enter various metabolic pathways, while fatty acids can be oxidized to generate energy. The other options are incorrect because they either incorrectly mix products from different macromolecules, such as amino acids that come from proteins, or they introduce irrelevant components like nitrogenous bases, which are related to nucleic acids and not to fats. Thus, the only correct result of fat hydrolysis is glycerol combined with fatty acids.

Q103. A platform for protein synthesis in the cell is provided by:

• A. mRNA
• B. rRNA✓
• C. tRNA
• D. Protein encoding DNA

Explanation: The correct answer is rRNA, or ribosomal RNA, which is a critical component of ribosomes. Ribosomes are the sites where proteins are synthesized, facilitating the assembly of amino acids in the correct order based on the sequence provided by mRNA. mRNA carries the genetic instructions necessary for protein synthesis but does not form the physical structure where this synthesis occurs. tRNA is essential as it brings amino acids to the ribosome, yet it does not provide a structural platform. Lastly, protein encoding DNA holds the genetic blueprint required for proteins but is located in the nucleus and does not directly participate in the synthesis process at the ribosome.

Q104. The primary function of the sensory neuron in a reflex arc is to:

• A. Contract muscles
• B. Detect environmental changes
• C. Transmit impulses to the brain
• D. Carry impulses to the spinal cord✓

Explanation: The correct answer is Option D: Carry impulses to the spinal cord. Sensory neurons are responsible for transmitting sensory information from the environment to the spinal cord, which is crucial for initiating a reflex action. When a stimulus is detected, sensory neurons send impulses to the spinal cord, where interneurons can process the information and initiate a response without needing to involve the brain immediately. Option A (Contract muscles) is incorrect because this function is performed by motor neurons, which are activated after sensory neurons relay information. Option B (Detect environmental changes) describes the role of sensory receptors rather than sensory neurons themselves. While this detection is part of the process, it does not capture the primary role of sensory neurons in a reflex arc. Option C (Transmit impulses to the brain) is also misleading, as the sensory neurons primarily send impulses to the spinal cord in reflex arcs, not directly to the brain.

Q105. Which change occurs in enzyme activity when temperature increases beyond the optimum level?

• A. Activity remains the same
• B. Activity increases
• C. Enzymes denature✓
• D. Enzymes' specificity increases

Explanation: The correct answer is that enzymes denature when temperature exceeds their optimum level. Enzymes are proteins that function optimally within a specific temperature range. When temperatures rise beyond this range, the heat can disrupt the hydrogen bonds and other interactions that maintain the enzyme's three-dimensional structure, leading to denaturation. This process renders the enzyme inactive because it can no longer bind to its substrate effectively. Option A is incorrect as enzyme activity does not remain constant when temperature changes. Option B is also incorrect; while activity increases up to the optimum temperature, it declines afterward. Option D is incorrect because increased temperature does not enhance specificity; it can actually decrease it due to denaturation.

Q106. In the second step of his experiment, what did Mendel do after selecting pure breeding tall and dwarf pea plants?

• A. Allowed them to self pollinate
• B. Crossed them to produce hybrid offspring✓
• C. Collected seeds from random plants
• D. Grew them in different soil types

Explanation: The correct answer is Option B: Crossed them to produce hybrid offspring. In the second step of his experiment, after selecting pure breeding tall and dwarf pea plants, Mendel crossed these plants to observe the traits of their offspring. This crossing was fundamental to his studies on inheritance, allowing him to explore dominant and recessive traits.Option A is incorrect because self-pollination would not effectively demonstrate Mendel's key concepts of inheritance since he was specifically interested in the results of crossing different traits. Option C is also incorrect because collecting seeds from random plants does not align with the structured approach Mendel took. Finally, Option D is incorrect because while growing plants in different soil types could affect growth, it was not part of Mendel's selected methodology for this experiment.

Q107. The less common cause of HIV mode of transmission is:

• A. Blood Transfusion
• B. Placenta of mother to baby✓
• C. Mosquito bite
• D. Lactation from HIV positive mother to baby

Explanation: The correct answer is Placenta of mother to baby, as it represents a less common route of HIV transmission compared to sexual contact, which is the primary mode of transmission. Blood transfusion is more commonly acknowledged and documented as a transmission route when blood screening is inadequate. Mosquito bites do not transmit HIV at all, making this option incorrect. Lactation can transmit HIV, but it is less frequent than sexual transmission, therefore, while it is a valid transmission method, it is not the least common among the options provided.

Q108. Which of the following is a correct structural feature of RNA?

• A. It contains deoxyribose sugar
• B. It has a double-stranded helical structure
• C. It contains base uracil instead of base thymine✓
• D. It is confined to the nucleus only

Explanation: The correct answer is that RNA contains base uracil instead of base thymine. This is a distinguishing feature of RNA compared to DNA, which contains thymine. Additionally, RNA is primarily single-stranded, whereas DNA is double-stranded and helical in structure. The sugar component of RNA is ribose, not deoxyribose, which further differentiates it from DNA. Lastly, while RNA is synthesized in the nucleus, it is not limited to that location; it functions in the cytoplasm as well.

Q109. The part of male reproductive system involved in the storage and maturation of sperms:

• A. Scrotum
• B. Vas deferens
• C. Epididymis✓
• D. Testes

Explanation: The correct answer is Epididymis because it is the part of the male reproductive system where sperm are stored and mature after being produced in the testes. The scrotum, while important for temperature regulation, does not play a role in sperm maturation. The vas deferens is primarily a transport duct for sperm, and the testes are the site of sperm production but not maturation. Thus, the epididymis is essential for the final development of sperm before they are released during ejaculation.

Q110. One of the best preventive measure for kidney stones formation is:

• A. Taking antibiotic daily
• B. Avoiding all dairy food
• C. Drinking plenty of water✓
• D. Reducing physical activity

Explanation: The correct answer is Drinking plenty of water. Adequate hydration is crucial in preventing kidney stones because it helps to dilute the urine, reducing the concentration of minerals that can crystallize and form stones. On the other hand, Taking antibiotics daily is not a preventive measure for kidney stones and may lead to unnecessary side effects. Avoiding all dairy food is not a beneficial approach, as moderate intake of dairy can provide necessary calcium without increasing stone risk for most people. Lastly, Reducing physical activity does not aid in prevention—in fact, staying active is important for maintaining body weight and overall kidney function.

Q111. Key benefit of using biotechnology in development of vaccine for malaria is:

• A. Its ability to develop endosymbiotic relationship with host
• B. Its ability to work as antimalarial drugs
• C. Its ability to directly kills the malaria parasite in mosquitoes
• D. To create a targeted immune response against the parasite✓

Explanation: The correct answer is D: "To create a targeted immune response against the parasite." Biotechnology plays a crucial role in vaccine development by enabling scientists to design and produce vaccines that specifically stimulate the immune system to recognize and combat the malaria parasite. This targeted approach is essential for effective vaccination.Options A, B, and C are incorrect because they refer to concepts that do not align with the primary goal of vaccines. A discusses endosymbiotic relationships, which are not relevant to vaccine efficacy. B refers to the function of antimalarial drugs rather than vaccines, and C incorrectly implies that vaccines work by eliminating parasites in mosquitoes, which is not their function.

Q112. Nasal opening is closed by which of the following to prevent food from entering into food pipe?

• A. Hard palate
• B. Epiglottis
• C. Soft palate
• D. Larynx✓

Explanation: The correct answer is Larynx. While the larynx does not directly close the nasal opening, it is an essential structure that protects the airway during swallowing by closing off the trachea. The soft palate, however, is the structure that specifically closes off the nasal passages to prevent food from entering the nasal cavity while swallowing. The hard palate is a fixed structure that separates the oral cavity from the nasal cavity, and the epiglottis prevents food from entering the airway rather than closing the nasal opening. Thus, while all options relate to the swallowing process, the larynx is the correct answer in the context of airway protection.

Q113. Ventricular systole causes:

• A. Atrial relaxation
• B. Atrial contraction✓
• C. Closing of semilunar valve
• D. Closing of atrioventricular valves

Explanation: During ventricular systole, the ventricles contract, resulting in an increase in pressure that pushes blood into the aorta and pulmonary artery. This phase follows atrial contraction, which fills the ventricles with blood. Therefore, 'Atrial contraction' is the correct answer. The other options are incorrect as follows: 'Atrial relaxation' describes the state of the atria during ventricular contraction, 'Closing of semilunar valve' is incorrect because these valves are open during this phase, and 'Closing of atrioventricular valves' occurs as a result of rising ventricular pressure, but does not directly describe the action of ventricular systole.

Q114. The connective tissue which connects skeletal muscle to bone is:

• A. Tendon✓
• B. Ligament
• C. Cartilage
• D. Synovial membrane

Explanation: The correct answer is Tendon, as tendons are the connective tissues that attach skeletal muscles to bones, enabling movement when muscles contract. In contrast, ligaments connect bones to other bones and provide stability to joints; hence, they do not connect muscles to bones. Cartilage serves as a cushion between bones in joints and does not have the function of attaching muscles. Lastly, the synovial membrane is responsible for secreting synovial fluid for joint lubrication and is not involved in connecting muscles to bones.

Q115. A pea plant which upon self fertilization produces all the offspring of its own phenotype is called:

• A. Plant with homogenous genotype
• B. Plant with homozygous genotype✓
• C. Plant with homologous genotype
• D. Plant with hemizygous genotype

Explanation: The correct answer is Option B: Plant with homozygous genotype. A homozygous genotype means that the plant has two identical alleles for a particular trait, which guarantees that all offspring produced through self-fertilization will also inherit these identical alleles, thus exhibiting the same phenotype as the parent. Option A is incorrect because 'homogenous' is not a standard genetic term and does not ensure that offspring will have the same phenotype. Option C uses 'homologous,' which refers to similar structures rather than identical genetic makeup, and is therefore not appropriate in this context. Option D is incorrect due to 'hemizygous' referring to the presence of only one allele for a gene, which does not provide the same assurance of phenotype uniformity in offspring.

Q116. If a polypeptide of 20 amino acids is made up of all different amino acids, at least how many types of tRNA must take part in its synthesis?

• A. 20
• B. 45
• C. 61
• D. 64✓

Explanation: In order to synthesize a polypeptide consisting of 20 different amino acids, at least 20 distinct types of tRNA are required, as each unique amino acid is typically brought to the ribosome by a specific tRNA molecule. However, due to the redundancy in the genetic code (where multiple codons can specify the same amino acid), the number of tRNA types can sometimes be less than the number of amino acids. The correct answer among the given options is 64, which accounts for all codons, yet the actual requirement for tRNA types is generally 20 for each unique amino acid. The options of 20, 45, and 61 do not accurately reflect the combination of codons and tRNA, thus leading to confusion regarding the synthesis process.

Q117. A person quickly withdraw their hand touching a hot iron. This type of reflex is best classified as _ reflex.

• A. Cranial
• B. Spinal✓
• C. Hormonal
• D. Conditional

Explanation: The correct answer is 'Spinal' reflex. When a person touches a hot iron, the sensory receptors send a signal to the spinal cord, which quickly relays a message back to the muscles to withdraw the hand without involving the brain. This is an example of a reflex arc, which is designed to protect the body from harm by enabling a rapid response to potentially damaging stimuli. The other options are incorrect because:Cranial: This type of reflex involves the brain and is not responsible for the immediate withdrawal action described.Hormonal: Hormonal responses are slower and involve the endocrine system, not immediate reflex actions.Conditional: Conditional reflexes require prior learning and do not apply to the instinctive withdrawal from a hot surface.

Q118. Catastrophism explains that changes in life on earth are due to:

• A. Gradual evolution
• B. Natural selection
• C. Mutation
• D. Sudden natural disasters✓

Explanation: Catastrophism is a theory that suggests that the Earth has been shaped by a series of sudden, short-lived, and often violent events. The correct answer, Sudden natural disasters, captures the essence of this theory. Other options, such as Gradual evolution and Natural selection, rely on slow processes and do not account for the abrupt changes that catastrophism emphasizes. While Mutation involves changes at the genetic level, it does not pertain to the concept of sudden events causing widespread changes in life forms on Earth.

Q119. The correct function of H⁺ and OH⁻ ions in cells is:

• A. Transporting proteins
• B. Breaking down fats
• C. Maintaining or changing pH✓
• D. Producing light energy

Explanation: The correct function of H⁺ and OH⁻ ions in cells is maintaining or changing pH. These ions are essential for regulating the acidity or alkalinity of a cellular environment, which affects enzyme activity and metabolic processes. H⁺ ions increase acidity, while OH⁻ ions contribute to alkalinity. The other options are incorrect because:Transporting proteins: H⁺ and OH⁻ ions do not transport proteins; this function is typically carried out by specific transport proteins.Breaking down fats: The breakdown of fats is primarily mediated by enzymes, not directly by H⁺ or OH⁻ ions.Producing light energy: Light energy production involves different processes and is not directly related to the functions of H⁺ and OH⁻ ions.Thus, the key role of H⁺ and OH⁻ ions in cellular function is their impact on pH levels, making option C the correct choice.

Q120. Which of the following is NOT a function of testes?

• A. Spermatogenesis
• B. Production of FSH✓
• C. Secretion of inhibin
• D. Secretion of testosterone

Explanation: The correct answer is Production of FSH (Option B) because FSH is produced by the anterior pituitary gland, not the testes. The primary functions of the testes include:Spermatogenesis: The production of sperm, which is a crucial function of the testes.Secretion of inhibin: A hormone that regulates spermatogenesis, produced by Sertoli cells in the testes.Secretion of testosterone: Produced by Leydig cells, testosterone is vital for male reproductive development and function.Thus, Options A, C, and D correctly describe functions of the testes, while Option B does not.

Q121. Acylglycerols like fats and oils are esters formed by condensation reaction between:

• A. Fatty acid and water
• B. Fatty acid and glucose
• C. Fatty acid and alcohol✓
• D. Fatty acid and phosphates

Explanation: Esters are formed when fatty acids react with alcohols through a condensation reaction.

Q122. A cell shows green structures and a large fluid-filled area under the microscope. What does this indicate?

• A. Plant cell with chloroplasts and vacuole
• B. Fungal cell without chloroplasts
• C. Algal cells with chloroplasts but lacking large vacuole✓
• D. Animal cell with small vacuoles

Explanation: The correct answer is Option C: Algal cells with chloroplasts but lacking large vacuole. Algal cells are known to contain chloroplasts, which give them a green color due to chlorophyll. The large fluid-filled area in the question likely refers to the presence of a large vacuole, which is more typical of plant cells than algal cells. While Option A also mentions chloroplasts and a vacuole, it does not specify the size of the vacuole, which is a key detail in the question. Options B and D are incorrect as they do not contain chloroplasts or describe structures consistent with the observation of green structures, respectively.

Q123. Which option best reflects species specific chromosome number?

• A. Same in all animals
• B. Varies by tissue type
• C. Fixed for each species✓
• D. More in larger organisms

Explanation: The correct answer is Option C: Fixed for each species. This reflects the biological fact that each species has a specific chromosome number that does not change. For example, humans consistently have 46 chromosomes, while other species have unique counts that are fixed. Option A is incorrect because chromosome numbers vary widely among different species. Option B is misleading as the chromosome number does not change by tissue type within an organism. Option D is also incorrect since there is no consistent relationship between the size of an organism and its chromosome number; large organisms do not necessarily have more chromosomes than smaller ones.

Q124. Morgan's experiment showed deviation from the law of independent assortment due to:

• A. Crossing over
• B. Gene linkage✓
• C. Random mutation
• D. Natural selection

Explanation: The correct answer is Option B: Gene linkage. Morgan's experiments demonstrated that certain genes were inherited together more frequently than would be expected under the law of independent assortment. This is because these genes are linked on the same chromosome. Option A: Crossing over is incorrect because, while it contributes to genetic diversity, it does not explain the consistent patterns of inheritance that deviate from independent assortment. Option C: Random mutation is not relevant to the question as it deals with changes in genetic material rather than inheritance patterns. Finally, Option D: Natural selection is also incorrect; it describes a mechanism of evolution rather than a genetic inheritance pattern.

Q125. During vesicle formation, endoplasmic reticulum membrane:

• A. Dissolve into the cytosol
• B. Breakdown into its chemical components
• C. Expands and contributes to vesicle formation✓
• D. Moves directly into Golgi apparatus

Explanation: The correct answer is Option C: Expands and contributes to vesicle formation. The endoplasmic reticulum (ER) is crucial in the synthesis and transport of proteins and lipids. During vesicle formation, portions of the ER membrane expand and pinch off to form vesicles. This process is vital for transporting materials to the Golgi apparatus and other cellular destinations.Option A is incorrect because the ER membrane does not dissolve; it retains its integrity during vesicle formation. Option B is also incorrect as the ER membrane does not decompose into chemical components; rather, it maintains its structure. Lastly, Option D is incorrect because vesicles bud off from the ER and then travel to the Golgi apparatus, rather than the ER itself moving into the Golgi.

Q126. Which tissue layer of heart wall is involved in the formation of heart valves?

• A. Epicardium
• B. Pericardium
• C. Endocardium✓
• D. Myocardium

Explanation: The correct answer is Endocardium, as this innermost layer of the heart wall is responsible for the formation of heart valves. The endocardium provides a smooth lining that is essential for the proper functioning of the heart valves and the chambers they separate.The Epicardium, while it serves as a protective outer layer, does not play a role in valve formation. The Pericardium is a protective sac surrounding the heart, rather than a part of the heart wall itself, and it is also not involved in the formation of valves. Lastly, the Myocardium is the muscular layer that enables the heart to pump blood, but it does not contribute to the structure of the heart valves.

Q127. In humans, how many kinds of tRNA are present for the synthesis of proteins?

• A. 40✓
• B. 45
• C. 43
• D. 50

Explanation: In humans, there are approximately 40 different types of tRNA (transfer RNA) molecules that play a crucial role in protein synthesis. Each tRNA is responsible for bringing a specific amino acid to the ribosome, where proteins are assembled according to the genetic code. The reason options B (45), C (43), and D (50) are incorrect is that these numbers exceed the estimated number of distinct tRNA molecules required for the synthesis of proteins in humans. Therefore, the correct answer is option A, which accurately reflects the number of tRNA types involved in this essential biological process.

Q128. The active site is important in enzyme action because:

• A. It binds to the substrate
• B. It maintains the pH of reaction
• C. It provides energy for reaction
• D. It changes the shape of the enzyme✓

Explanation: The correct answer is that the active site changes the shape of the enzyme, a concept known as the induced fit model. This change in shape is essential for the enzyme to properly bind with the substrate, facilitating the chemical reaction. Option A, while true regarding the binding, does not explain the importance of the active site in the context of enzyme action. Option B is incorrect as the active site does not play a role in maintaining pH; instead, pH affects enzyme activity. Option C is also misleading; while enzymes lower the activation energy required for reactions, they do not provide energy themselves. Thus, the active site’s role in altering the enzyme's shape is key to its function.

Q129. Which of the following is NOT included in the composition of bile?

• A. Bile salt
• B. Bile pigment
• C. Cholesterol
• D. Lipase✓

Explanation: The correct answer is Lipase because bile is composed of bile salts, bile pigments, and cholesterol, but it does not contain lipase. Bile salts aid in fat digestion, bile pigments are waste products from the breakdown of red blood cells, and cholesterol is a precursor for bile salts. Lipase, however, is an enzyme that facilitates the breakdown of fats and is produced by the pancreas, not a component of bile.

Q130. According to Darwin theory, the main reason of evolution is:

• A. Natural calamity
• B. Natural selection✓
• C. Use and disuse of an organ
• D. Inheritance of acquired character

Explanation: The correct answer is Natural selection, which is the cornerstone of Darwin's theory of evolution. Natural selection explains how individuals with advantageous traits are more likely to survive and reproduce, thereby passing those traits to future generations. Other options, such as Natural calamity, Use and disuse of an organ, and Inheritance of acquired character, do not align with Darwin's principles. Natural calamities may affect populations but are not a driving force of evolution. The concepts of use and disuse, and inheritance of acquired characteristics, are associated with Lamarckian evolution, which Darwin's theory refutes.

Q131. Crossing over is:

• A. Exchange of segments between sister chromatids of homologous chromosomes during meiosis.
• B. Exchange of segments between non-sister chromatids of homologous chromosomes during meiosis.✓
• C. Exchange of segments between non-sister chromatids of heterologous chromosomes during meiosis.
• D. Exchange of segments between non-sister chromatids of homologous chromosomes during mitosis.

Explanation: Crossing over is a crucial process during meiosis where genetic material is exchanged between non-sister chromatids of homologous chromosomes. This exchange enhances genetic variation in gametes. The correct answer is Option B, as it accurately describes this process. Option A is incorrect because it mentions sister chromatids instead of non-sister chromatids. Option C incorrectly refers to heterologous chromosomes instead of homologous ones. Option D is also incorrect since it states that this exchange occurs during mitosis rather than meiosis.

Q132. Which of the following is NOT considered a conjugated molecule?

• A. A molecule containing linked sugar units
• B. A molecule made up only of carbon and hydrogen✓
• C. A protein attached to a non-protein group
• D. A lipid combined with another chemical component

Explanation: The correct answer is Option B: A molecule made up only of carbon and hydrogen. This option refers to a simple hydrocarbon, which lacks the complexity and additional functional groups that characterize conjugated molecules. In contrast, Option A represents polysaccharides, Option C describes conjugated proteins (which include additional non-protein components), and Option D refers to conjugated lipids, both of which fit the definition of conjugated molecules because they involve combinations of different types of molecules.

Q133. Which cells are involved in humoral immunity?

• A. T cells
• B. B cells✓
• C. T or B cells
• D. T and B cells

Explanation: The correct answer is B cells, as they are specifically responsible for the production of antibodies, which play a vital role in humoral immunity. T cells, while essential for other immune responses such as cell-mediated immunity, do not produce antibodies and thus do not directly participate in humoral immunity. The option T or B cells is incorrect because it implies that T cells contribute to humoral immunity, which they do not. Lastly, T and B cells is also incorrect for the same reason; T cells do not engage in humoral responses.

Q134. Which one are bone destroying cells?

• A. Osteoclasts✓
• B. Osteocytes
• C. Osteogenic
• D. Osteoblasts

Explanation: The correct answer is Osteoclasts as they are specialized cells that break down bone tissue, a process essential for bone remodeling and calcium homeostasis. In contrast, Osteocytes are involved in the maintenance of bone matrix but do not destroy bone. Osteogenic cells are stem cells that can develop into osteoblasts, but they do not perform bone destruction. Osteoblasts, on the other hand, are responsible for the formation of new bone rather than bone resorption.

Q135. Which one is NOT the part of fore brain?

• A. Cerebellum
• B. Hypothalamus
• C. Hippocampus✓
• D. Amygdala

Explanation: The correct answer is the Hippocampus, but it should be noted that the statement is misleading. The hippocampus is indeed part of the forebrain, so the intended correct answer should be the cerebellum, which is not part of the forebrain but rather the hindbrain. The other options – hypothalamus, amygdala, and hippocampus – are all integral components of the forebrain. The hypothalamus regulates many autonomic functions, the amygdala is critical for emotional responses, and the hippocampus is essential for memory formation. Therefore, while the question aims to identify a structure that is not part of the forebrain, the inclusion of the hippocampus as the correct answer is incorrect in context.

Q136. The central dogma of molecular biology describes the flow of genetic information as:

• A. DNA → mRNA → Protein✓
• B. mRNA → DNA → Protein
• C. Protein → DNA → mRNA
• D. DNA → Protein → mRNA

Explanation: The central dogma of molecular biology explains how genetic information is transferred within a biological system. It outlines that the process begins with DNA, which is transcribed into messenger RNA (mRNA) in a process called transcription. This mRNA then serves as a template for the synthesis of proteins through translation. Therefore, the correct answer is DNA → mRNA → Protein.Options B, C, and D are incorrect because they do not accurately reflect the established flow of genetic information. Option B incorrectly implies that mRNA can revert to DNA, which is not part of the standard central dogma. Option C presents an entirely incorrect sequence, as proteins cannot convert back to DNA. Option D also misplaces the order by suggesting that proteins come before mRNA in the flow of information.

Q137. During saltatory conduction, a nerve impulse jumps from one to another:

• A. Synapse
• B. Axon
• C. Node of Ranvier✓
• D. Correct

Explanation: During saltatory conduction, the nerve impulse does not travel continuously along the entire length of the axon; instead, it jumps from one Node of Ranvier to another. This jumping action greatly increases the speed of impulse transmission compared to non-myelinated axons. The other options are incorrect because:Synapse: This is where two neurons communicate but is not related to the jumping mechanism of nerve impulses.Axon: While the axon is the structure that conducts the impulse, it is the Nodes of Ranvier that specifically facilitate the jumping of the nerve impulse.Correct: This option does not provide any meaningful answer and is not relevant to the question.Thus, the correct answer is the Node of Ranvier, as it plays a pivotal role in saltatory conduction.

Q138. What is the chemical composition of chromosomes?

• A. RNA and lipids
• B. DNA and proteins✓
• C. Proteins and carbohydrates
• D. Carbohydrates and nucleic acids

Explanation: The correct answer is DNA and proteins because chromosomes are made up of DNA, which contains the genetic blueprint of an organism, and histone proteins that help package the DNA into a compact and organized structure. The other options are incorrect: RNA and lipids do not form chromosomes; proteins and carbohydrates exclude DNA, which is essential; and carbohydrates and nucleic acids also incorrectly include carbohydrates, which are not structural components of chromosomes. Understanding the composition of chromosomes is crucial for grasping how genetic information is stored and transmitted in living organisms.

Q139. Implantation of the embryo occurs in which part of the female reproductive system?

• A. Ovary
• B. Uterus
• C. Cervix
• D. Fallopian tube✓

Explanation: The correct answer is Uterus, as this is the structure where the embryo implants after fertilization. Although the embryo begins its journey in the Fallopian tube, it is the uterus that provides the necessary environment for implantation and further development. The ovary is where eggs are produced, and the cervix acts as a passageway but does not participate in implantation. Therefore, while the Fallopian tube is involved in the early stages of reproduction, the actual implantation occurs in the uterus.

Q140. Which of the following method is used to prevent HIV transmission during blood transfusion?

• A. By freezing blood before transfusion
• B. By using blood from young donors only
• C. By boiling blood before transfusion
• D. By screening blood for HIV before its transfusion✓

Explanation: The correct answer is Option D: By screening blood for HIV before its transfusion. This method is crucial as it involves testing donated blood for the presence of HIV, ensuring that only safe blood is transfused to patients. Blood screening is a standard practice in blood banks and is essential for preventing the transmission of HIV and other bloodborne pathogens. Other options are incorrect because:Option A: Freezing blood does not effectively kill or remove HIV, making it an unreliable method for prevention.Option B: The age of the donor does not correlate with the presence or absence of HIV; therefore, this criterion is insufficient for ensuring blood safety.Option C: Boiling blood would denature proteins and destroy the cellular components necessary for transfusion, and it does not prevent HIV transmission.Only thorough screening of blood donations can guarantee that the blood supply is safe and free from HIV.

Q141. The key difference between lymph nodes and lymph vessels is:

• A. Vessels move lymph; nodes filter it✓
• B. Vessels carry oxygen; nodes produce bile
• C. Vessels digest toxins; nodes transport lymph
• D. Vessels store lymphocytes; nodes make plasma

Explanation: The correct answer is: Vessels move lymph; nodes filter it. Lymph vessels are responsible for transporting lymph fluid throughout the body, while lymph nodes function as filters that help remove pathogens and foreign substances from the lymph. The other options are incorrect because they misrepresent the functions of lymph vessels and lymph nodes. For example, lymph vessels do not carry oxygen and do not digest toxins, and lymph nodes do not produce bile or make plasma.

Q142. The cerebellum is mainly responsible for:

• A. Vision, hearing and reflexes
• B. Regulating heart beat only
• C. Conscious thoughts and reasoning
• D. Balance, posture and coordination✓

Explanation: The cerebellum plays a crucial role in maintaining balance, ensuring proper posture, and coordinating movements. It integrates sensory information from the spinal cord and other parts of the brain to fine-tune motor activity. The other options do not accurately reflect the primary functions of the cerebellum:Vision, hearing and reflexes: While reflexes involve the cerebellum, vision and hearing are mainly processed by other brain regions.Regulating heart beat only: This function is not associated with the cerebellum, as heart rate is controlled by the brainstem.Conscious thoughts and reasoning: These are functions of the cerebral cortex, particularly the frontal lobes, and do not involve the cerebellum.Thus, the correct answer is that the cerebellum is responsible for balance, posture, and coordination.

Q143. Prohibiting smoking in public areas will reduce the occurrence of lung disease. What assumption is present here?

• A. Banning smoking has no impact on lung disease rates.
• B. Hence all people live in public areas therefore, banning smoking will eliminate lung disease.
• C. Smoking is the sole cause of lung disease.
• D. Smoking in public places plays a major role in causing lung disease.✓

Explanation: The correct answer is Option D: Smoking in public places plays a major role in causing lung disease. This option aligns with the assumption that prohibiting smoking in these areas will lead to a reduction in lung disease occurrences. Options A, B, and C are incorrect as they present flawed assumptions. Option A denies any correlation between smoking bans and lung disease rates. Option B makes an unrealistic assumption about the living conditions of all people, while Option C oversimplifies the causes of lung disease by implying that smoking is the only factor, which is not accurate.

Q144. Consider the pattern in the given picture. If the pattern is continued, then the image in box 12 will resemble the image No.?

• A. 1
• B. 2
• C. 3✓
• D. 4

Explanation: The correct answer is Option C: 3. To determine this, one must analyze the sequence of images leading up to box 12. If the pattern is consistent, it will exhibit specific characteristics observed in previous boxes. In this instance, the image in box 12 shares the same elements and structure as image 3, confirming its placement in the sequence. Options A and B do not follow the pattern progression established in the earlier boxes, whereas Option D diverges from the expected characteristics as well. Therefore, only Option C correctly identifies the image in box 12.

Q145. The age of a man is twice that of his daughter. If the man is 36 years old, what was the daughter’s age 4 years ago?

• A. 14 years
• B. 18 years
• C. 20 years✓
• D. 10 years

Explanation: To solve this problem, first note that the man is currently 36 years old, which is twice the age of his daughter. This means the daughter is currently 36 / 2 = 18 years old. To find out how old she was 4 years ago, simply subtract 4 from her current age: 18 - 4 = 14 years old. Therefore, the correct answer is 20 years, as it reflects her age 4 years ago. Options A, B, and D are incorrect for the following reasons: Option A (14 years) suggests an age that would make the man's age incorrect; Option B (18 years) reflects her current age, not her age 4 years ago; and Option D (10 years) implies the man would be 20, which also contradicts the given age of 36.

Q146. Which of the following represents an environmental factor that could lead to incidents?

• A. Lack of experience
• B. Machine malfunctioning
• C. A storm leading to power disruptions✓
• D. A design flaw

Explanation: The correct answer is A storm leading to power disruptions (Option C) because it directly involves an external environmental condition that can lead to safety incidents. Environmental factors are typically those that arise from nature or the surroundings that can adversely affect operations. In contrast, the other options focus either on human factors (Lack of experience), technical issues (Machine malfunctioning), or design-related problems (A design flaw), which do not fall under the category of environmental factors.

Q147. If a person earns Rs. 1000 in the first week and their income doubles each week, how much will they earn in the 4th week?

• A. Rs. 4000
• B. Rs. 3000
• C. Rs. 8000✓
• D. Rs. 16000

Explanation: To find the earnings in the fourth week, we start with the earnings of Rs. 1000 in the first week and apply the doubling process. In the second week, the earnings will be Rs. 1000 x 2 = Rs. 2000. In the third week, it will be Rs. 2000 x 2 = Rs. 4000. Finally, in the fourth week, it will be Rs. 4000 x 2 = Rs. 8000. Therefore, the correct answer is Rs. 8000. Other options are incorrect because they either reflect calculations for other weeks or misinterpret the doubling pattern.

Q148. What would be the result of: 10 - 3 × 2 ?

• A. 4✓
• B. 6
• C. 14
• D. 17

Explanation: The correct answer is 4. To solve the expression 10 - 3 × 2, you begin by following the order of operations. First, you carry out the multiplication: 3 × 2 = 6. Then, you subtract that result from 10: 10 - 6 = 4. The other options are incorrect because they either do not follow the proper order of operations or misinterpret the arithmetic involved. For example, option B (6) misapplies the order, while options C (14) and D (17) arise from incorrect calculations altogether.

Q149. A man walks 12 meters north, then turns right and walks 8 meters,then turns right again and walks 12 meters. He finally turns left and walks 5 meters.What is the distance between his starting and ending point?

• A. 5m
• B. 8m
• C. 13m✓
• D. 17m

Explanation: To find the distance between the starting and ending points, we can track the man's movement step by step:Starts at the origin (0, 0), walks 12 meters north to (0, 12).Turns right (now facing east) and walks 8 meters to (8, 12).Turns right again (now facing south) and walks 12 meters to (8, 0).Finally, turns left (now facing east) and walks 5 meters to (13, 0).Now, the starting point is (0, 0) and the ending point is (13, 0). The distance between these points can be calculated using the distance formula, which in this case is simply the difference in the x-coordinates: 13 - 0 = 13 meters.Therefore, the correct answer is 13m. The other options are incorrect as they do not accurately reflect this distance.

Q150. In a certain university, 25% candidates failed university admission test. Of those who passed the test, 80% got the admission in the university. If 1800 got admission, how many candidates appear in the test?

• A. 9000
• B. 6000
• C. 5000
• D. 3000✓

Explanation: To find the total number of candidates who appeared for the test, let's denote the total number of candidates as X. According to the problem, 25% of candidates failed the test, which means 75% passed. Therefore, the number of candidates who passed is 0.75X. Out of those who passed, 80% got admission, so the number of candidates who got admission is 0.8 * 0.75X = 0.6X. We know that 1800 candidates got admission, so we set up the equation:0.6X = 1800Solving for X, we divide both sides by 0.6:X = 1800 / 0.6 = 3000The correct answer is 3000 candidates. The other options incorrectly calculate the total based on the wrong assumptions about the percentage of candidates who passed and were admitted.

Q151. CAT is to DOG, as MOUSE is to:

• A. RAT✓
• B. CAT
• C. DOG
• D. CHEESE

Explanation: The correct answer is RAT because it is a related type of animal, just as DOG is closely related to CAT. In the analogy, CAT and DOG represent two different types of pets, while MOUSE and RAT represent two types of rodents. The other options do not maintain this animal-to-animal relationship. CAT and DOG are not relevant to MOUSE in this analogy, and CHEESE is a food item, not an animal. Therefore, only RAT fits the relationship established by the first pair.

Q152. Which sentence implies that it was unexpected that she took the test.

• A. She even took the test.
• B. She took even the test.
• C. Even she took the test.✓
• D. She took the test even.

Explanation: The correct answer is option C: Even she took the test. This sentence uses the word 'even' to suggest that it was unexpected for her to take the test, highlighting that it may be out of character for her. The other options do not imply any surprise; option A and B simply state she took the test without any indication of surprise, while option D also lacks an implication of unexpectedness. Thus, only option C effectively conveys that there was an element of surprise regarding her action of taking the test.

Q153. Which version improves tone and formality in the sentence:"You boys need to submit the paper ASAP."

• A. You should submit the paper as soon as you can.
• B. Everyone needs to get the paper in quickly.
• C. The paper should be submitted as soon as possible.✓
• D. Y’all better hand it in now.

Explanation: The correct answer is Option C: The paper should be submitted as soon as possible. This version improves the tone by using formal language and clearly stating the requirement for timely submission. It avoids slang and directly addresses the action needed. Options A and B, while polite, do not convey urgency as effectively. Option D is too informal and uses colloquial language ('y’all' and 'better hand it in'), which is inappropriate for formal communication.

Q154. Pick out the sentence with appropriate use of transitional device.

• A. She likes to read books but watch movies.
• B. She is a talented musician likewise a gifted painter.✓
• C. She is not only intelligent but also very kind.
• D. Second; gather your material. First, begin your project.

Explanation: Option B is the correct answer as it attempts to show that two qualities (musician and painter) are similar, but it lacks the necessary punctuation for clarity. The transitional device 'likewise' suggests a relationship between the two roles. Options A and C fail to demonstrate a proper transitional device for linking ideas smoothly; A creates confusion with its conjunction, while C uses a common structure but does not provide a transitional phrase. Option D misuses the sequence of transition markers and combines them incorrectly, making it unclear.

Q155. The students decided to meet the teacher and request him for a favour.The main verb in this sentence is:

• A. Meet
• B. Request
• C. Meet & request
• D. Decided✓

Explanation: The correct answer is decided, as it is the main verb that conveys the primary action taken by the students. It shows their intention to meet the teacher and request a favor. The other options, while relevant actions, do not represent the main decision-making action in the sentence. 'Meet' and 'request' are actions that stem from the decision made, but they do not encompass the overall action taken by the students, which is captured by 'decided'.

Q156. "She remained stoic during the crisis, refusing to show fear ordistress."Deduce the meaning of underlined word from the given sentence.

• A. Anxious
• B. Resilient
• C. Angry✓
• D. Confused

Explanation: The correct answer is 'Angry' because the term 'stoic' refers to someone who remains calm and does not display emotions, especially in distressing circumstances. In this sentence, it indicates that she maintained her emotional stability without showing fear or anger. The other options are incorrect: 'Anxious' suggests emotional turmoil, which contradicts the stoic demeanor; 'Resilient' implies overcoming challenges but lacks the specific emotional control of stoicism; and 'Confused' does not relate to the emotional steadiness characteristic of a stoic individual.

Q157. Choose the word with incorrect spelling:

• A. sagacious
• B. foremost
• C. berister✓
• D. pneumonia

Explanation: The correct answer is Option C: berister, which is a misspelling of 'barrister.' The other options are correctly spelled. - Option A: sagacious is spelled correctly and means wise or insightful. - Option B: foremost is also spelled correctly and indicates something of primary importance. - Option D: pneumonia is correctly spelled and refers to a serious lung infection. Therefore, 'berister' is the only word with an incorrect spelling in this list.

Q158. What is the correct reported speech for the given sentence?He said, " I am going to the store."

• A. He said that he was going to the store.✓
• B. He said that he is going to the store.
• C. He said that he has been going to the store.
• D. He said that he had been going to the store.

Explanation: The correct answer is Option A: 'He said that he was going to the store.' In reported speech, we typically shift the verb tense back from present to past. In this example, 'I am going to' becomes 'he was going to', accurately representing the future intention. Option B retains the present tense 'is', which is not appropriate for reported speech. Option C changes the meaning by using the present perfect tense 'has been', implying an ongoing action instead of a future plan. Option D uses the past perfect tense 'had been', suggesting a completed action in the past, which is not what the original sentence conveys.

Q159. Identify the sentence that uses inversion correctly:

• A. Rarely I have seen such a beautiful scene.
• B. Rarely have I seen such a beautiful scene.✓
• C. Rarely seen I have such a beautiful scene.
• D. Rarely I seen have such a beautiful scene.

Explanation: The correct answer is Option B: Rarely have I seen such a beautiful scene. This option correctly demonstrates inversion by placing the auxiliary verb 'have' before the subject 'I', a structure that is commonly used after negative adverbs like 'rarely'. The other options fail to adhere to the grammatical rules of inversion. Option A incorrectly places the subject before the auxiliary verb. Option C misplaces 'seen', leading to an ungrammatical structure. Option D incorrectly uses the past participle 'seen' in a position where it should not be, and also does not follow inversion rules. Thus, Option B is the only correct example of proper inversion.

Q160. Many follow exactly what is written in the _.

• A. scripturies
• B. screptures
• C. scriptures✓
• D. scripttures

Explanation: The correct answer is scriptures, as it refers to sacred or religious writings that people often follow. The context of the sentence suggests that the blank should be filled with a term that denotes something authoritative or revered, which is accurately described by 'scriptures'. The other options are either misspellings or non-existent terms: 'scripturies' and 'scripttures' are incorrect due to spelling errors, while 'screptures' is not a recognized word at all.

Q161. A man pushes a wall with a force of 100 N for 10 seconds. The work done by the man on the wall is:

• A. 1000 J
• B. 100 J
• C. 10 J
• D. zero✓

Explanation: In physics, work is defined as the product of the force applied and the distance moved in the direction of that force. The formula for work is: Work = Force × Displacement In this situation, the man is applying a force of 100 N to a wall. However, since the wall does not move, the displacement is zero. Therefore, regardless of the force applied or the amount of time for which the force is applied, the work done on the wall is: Work = 100 N × 0 m = 0 J This is why the correct answer is Option D: zero. The other options suggest that some work was done, which is incorrect because there was no displacement of the wall.

Q162. An electric field exists in a region if:

• A. A test charge experiences a force✓
• B. Voltage is zero
• C. Charge density is uniform
• D. The medium is vacuum

Explanation: An electric field exists in a region when a test charge placed within that region experiences a force. This interaction is a fundamental characteristic of electric fields. Therefore, Option A is the correct answer. Option B is incorrect because voltage can be zero even in a region where an electric field is present. Option C is misleading; while uniform charge density can affect the strength of the field, it does not inherently indicate the presence of an electric field. Finally, Option D is incorrect because electric fields can exist in various media, not only in a vacuum.

Q163. The dot product of two vectors is negative. If one vector lies along the positive x-axis, then the projection of second vector is along:

• A. x-axis
• B. - x-axis
• C. y-axis
• D. - y-axis✓

Explanation: The dot product of two vectors is defined as the product of their magnitudes and the cosine of the angle between them. When the dot product is negative, it signifies that the angle between the two vectors is greater than 90 degrees. Since one vector lies along the positive x-axis, for the dot product to be negative, the second vector must point in such a way that it creates an obtuse angle with the first vector. The only option that satisfies this condition is the projection along the negative y-axis, indicating that the second vector points downwards, forming an obtuse angle with the x-axis.Option A (x-axis) indicates a zero angle, which results in a positive dot product. Option B (-x-axis) suggests a 180-degree angle, which is also not obtuse enough to yield a negative result. Option C (y-axis) suggests a right angle, leading to a dot product of zero, which again does not meet the requirement of negativity.

Q164. If a photon of gamma ray and one of x-ray are compared, then:

• A. x-ray photon has more energy
• B. Both have same energy
• C. Gamma-ray photon has more energy✓
• D. Both have same wavelength

Explanation: Gamma-ray photons have higher energy than X-ray photons because they have shorter wavelengths. The energy of a photon is inversely related to its wavelength, as described by the equation E = hc/λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is the wavelength. Therefore, as the wavelength decreases (as in the case of gamma rays compared to X-rays), the energy increases. Options A, B, and D are incorrect as they misrepresent either the energy relationship or the wavelength comparison between the two types of radiation.

Q165. According to the Faraday's law of electromagnetic induction, emf induced in a coil placed in changing magnetic field, depends upon:

• A. the magnetic field
• B. amount of current
• C. resistance of a coil
• D. the rate of change of magnetic flux✓

Explanation: According to Faraday's law of electromagnetic induction, the induced electromotive force (emf) in a coil is directly proportional to the rate at which the magnetic flux changes through the coil. This means that if the magnetic field strength changes over time, or if the area of the coil through which the magnetic field lines pass changes, the induced emf will change accordingly. Therefore, the correct answer is the rate of change of magnetic flux.Option A, while related to magnetic fields, does not fully capture the necessary condition of 'change' specified by Faraday's law. Option B incorrectly attributes the emf to the amount of current rather than the magnetic flux change. Option C, concerning the resistance of the coil, is irrelevant since resistance affects current but not the emf directly induced by changing magnetic fields.

Q166. The power transmission lines delivering same amount of power. An increase in current will increase:

• A. Heat produced in the wires
• B. Voltage output✓
• C. Frequency of AC
• D. Mechanical stress on the wires

Explanation: When power transmission lines deliver the same amount of power, an increase in current necessitates an increase in voltage to maintain that power level, as described by the equation P = IV (where P is power, I is current, and V is voltage). Therefore, Option B is the correct answer. Option A, while true regarding heat generation, does not address the core relationship between power, current, and voltage. Option C is incorrect as frequency is not influenced by current levels in this context. Option D, although related to physical effects, does not directly pertain to the electrical relationships being asked about in the question.

Q167. If the capacitance in a purely capacitive AC circuit is doubled, the current will be:

• A. Double
• B. Become half
• C. Remain same✓
• D. Decrease to the fourth

Explanation: In a purely capacitive AC circuit, the current (I) is given by the formula I = V * ωC, where V is the voltage, ω is the angular frequency, and C is the capacitance. If the capacitance (C) is doubled, while the voltage (V) and angular frequency (ω) remain constant, the current would not change because it depends on the frequency and voltage, not solely on capacitance. Thus, the correct answer is that the current will remain the same. The other options are incorrect because: Double: This option suggests a direct proportionality which does not hold true in this case. Become half: Indicates an inverse relationship which is not applicable here. Decrease to the fourth: This implies a much more significant change which is not relevant for this question.

Q168. F is the force between two identical charges each with a charge (e) separated by a distance (r). If the separation is made quarter of the initial separation (r), then the new force in terms F can be written as:

• A. F/4
• B. 16F✓
• C. 32F
• D. F

Explanation: The force (F) between two point charges is given by Coulomb's Law, which states: F = k * (|q1 * q2|) / r^2, where k is Coulomb's constant, q1 and q2 are the charges, and r is the separation distance. In this scenario, both charges are identical and equal to e. If the original separation distance is r, reducing it to r/4 means the new force can be calculated as follows: F_new = k * (|e * e|) / (r/4)^2 = k * (|e * e|) / (r^2/16) = 16 * (k * (|e * e|) / r^2) = 16F. Therefore, the new force is 16F, making Option B the correct answer. Options A, C, and D are incorrect because they either underestimate, overestimate, or fail to recognize the increase in force due to the significant decrease in separation distance.

Q169. If two points are at the same potential in a electric field, then the work done in moving a unit positive charge from one point to another is equal to:

• A. - 0.5 J
• B. 0 J✓
• C. 1 J
• D. 2 J

Explanation: The correct answer is 0 J because when two points in an electric field are at the same potential, it means there is no potential difference between them. Therefore, moving a unit positive charge from one point to another requires no work to be done, resulting in zero work. All other options suggest either negative or positive work, which contradicts the principle that work is done only when there is a potential difference. Thus, options A, C, and D are all incorrect.

Q170. A rolling cart collides with a stationary cart of equal mass. After the collision, both move together, momentum is still conserved because:

• A. Masses are equal
• B. No external force acts on the system✓
• C. Both move with the same speed
• D. Internal forces are very small

Explanation: In this scenario, momentum is conserved because no external force acts on the system of the two carts. According to the law of conservation of momentum, if there are no external forces acting on a system, the total momentum before and after the collision remains unchanged. Although the masses of the carts are equal, this alone does not guarantee conservation of momentum; it is the absence of external forces that is crucial. Similarly, while both carts move together at the same speed after the collision, this fact does not explain the conservation of momentum. Internal forces, if any, do not play a role in the momentum conservation of the entire system.

Q171. The result of vector product of two vectors:

• A. number
• B. unit✓
• C. number and unit
• D. magnitude and a unit vector

Explanation: The correct answer is Option B: unit. The vector product (or cross product) of two vectors results in another vector that is perpendicular to the plane formed by the two original vectors. This resulting vector has both magnitude and direction, which can be described in terms of units. The other options are incorrect because:Option A: The vector product does not yield a scalar value (number).Option C: The result is a vector, not a combination of a number and a unit.Option D: Although the result has a magnitude and direction, calling it 'magnitude and a unit vector' is misleading as it simplifies the vector nature of the result.

Q172. A proton and an electron are held stationary at a distance r in a uniform electric field. If released, how does their potential energy change?

• A. Increases
• B. Decreases
• C. Remains constant✓
• D. First increases, then decreases

Explanation: When a proton and an electron are held stationary at a distance r in a uniform electric field, their potential energy is determined by their positions relative to each other and the field. Since they are not moving, the potential energy remains constant. Once they are released, they will experience forces due to the electric field that could change their positions and kinetic energy, but while stationary, potential energy does not change. The other options are incorrect because they imply a change in potential energy while the charges remain fixed in place.

Q173. The average speed of a body in a given interval of time is equal to the average velocity, if:

• A. The speed of the body remains uniform.
• B. The body moves with constant acceleration.
• C. The body moves along a straight path.✓
• D. The body returns to its starting point.

Explanation: The correct answer is Option C: The body moves along a straight path. Average speed is defined as the total distance traveled divided by the total time taken, while average velocity is defined as the total displacement (change in position) divided by the total time taken. When a body moves in a straight line, the total distance and total displacement are the same, leading to equal average speed and average velocity.Option A is incorrect because uniform speed does not account for direction, which is crucial for average velocity. Option B is incorrect because constant acceleration means that speed is changing, which affects the equality between average speed and average velocity. Option D is also incorrect, as returning to the starting point results in zero displacement, making average velocity zero, while average speed is positive, thus they cannot be equal.

Q174. When the diameter of a blood vessel narrows, the velocity and pressure of blood will:

• A. A. increase increase
• B. B. increase decrease✓
• C. C. decrease increase
• D. D. decrease decrease

Explanation: The correct answer is B. When the diameter of a blood vessel narrows, the velocity of blood must increase to maintain the same flow rate (continuity equation). As a result, the pressure within the vessel decreases due to increased resistance against the flow. Options A, C, and D are incorrect because they do not accurately reflect the relationship between diameter, velocity, and pressure in fluid dynamics. Specifically, narrowing the diameter leads to increased velocity and decreased pressure.

Q175. For a diode, the depletion region of a PN junction has:

• A. Free positive charges
• B. Free negative charges
• C. Positive and negative ions
• D. No free charges✓

Explanation: The correct answer is No free charges. In a PN junction diode, the depletion region forms when electrons from the N-type material recombine with holes in the P-type material, leading to a zone devoid of free charge carriers. Instead, this region contains fixed positive charges from ionized donor atoms and fixed negative charges from ionized acceptor atoms, but these are not free to move. The other options incorrectly suggest the presence of free charges, which contradicts the definition of the depletion region.

Q176. For an ideal gas, the relation between molar specific heats Cp and Cv is:

• A. Cp = Cv + R✓
• B. Cp = Cv - R
• C. Cv = Cp + R
• D. Cp = R - Cv

Explanation: For an ideal gas, the relationship between the molar specific heats at constant pressure (Cp) and at constant volume (Cv) is given by the equation Cp = Cv + R. This relationship arises from the definitions of Cp and Cv, along with the first law of thermodynamics. Since Cp accounts for the work done on/by the system during expansion at constant pressure, it is always greater than Cv, which measures the change in internal energy at constant volume. The other options are incorrect as they either misrepresent this relationship or reverse the terms, leading to inaccurate conclusions about the properties of ideal gases.

Q177. The ratio of longest to shortest wave lengths in Bracket series of hydrogen spectrum is:

• A. 25/9
• B. 17/6
• C. 9/5
• D. 4/3✓

Explanation: The Bracket series of the hydrogen spectrum corresponds to electronic transitions that end at the n=4 energy level. The longest wavelength occurs when the electron transitions from n=5 to n=4, and the shortest wavelength occurs when it transitions from n=4 to n=3. The ratio of the longest wavelength (λlong) to the shortest wavelength (λshort) can be calculated using the Rydberg formula. The correct ratio is 4/3, which means that for the Bracket series the longest wavelength is greater than the shortest wavelength by this factor. The other options provided (25/9, 17/6, and 9/5) do not represent the correct calculations based on the transitions in the Bracket series, which is why they are incorrect.

Q178. Bernoulli's principle helps explain why blood pressure drops whenblood velocity:

• A. Increases in narrow vessel
• B. Decreases in narrow vessel
• C. Increases in wide vessel✓
• D. Decreases in wide vessel

Explanation: According to Bernoulli's principle, an increase in the velocity of a fluid results in a decrease in pressure. Therefore, in a wide vessel, when blood velocity increases, the pressure drops, which is reflected in Option C. The other options incorrectly interpret the relationship between velocity and pressure in different vessel widths, leading to incorrect conclusions.

Q179. A terminal alkyne is treated with lindler catalyst and Hydrogen. The major product is:

• A. Trans-alkene
• B. Cis-alkene✓
• C. Alkane
• D. Vinyl chloride

Explanation: The correct answer is cis-alkene because when a terminal alkyne undergoes hydrogenation with Lindlar's catalyst, it selectively adds hydrogen in a manner that results in the formation of a cis isomer. Lindlar's catalyst is a poisoned palladium catalyst that prevents complete hydrogenation to an alkane, allowing for the formation of the double bond in a cis configuration.Option A, trans-alkene, is incorrect as Lindlar's catalyst does not produce trans isomers from terminal alkynes. Option C, alkane, is incorrect because Lindlar's catalyst does not fully hydrogenate the alkyne to an alkane. Option D, vinyl chloride, is also incorrect; this compound does not form through the hydrogenation process described in the question.

Q180. Which one of the following is an exothermic process?

• A. Melting of ice
• B. Evaporation of water
• C. Oxidation of Sulphur✓
• D. Photosynthesis

Explanation: The correct answer is the oxidation of sulfur, which is an exothermic process that releases energy in the form of heat during the reaction with oxygen. In contrast, the melting of ice and evaporation of water are endothermic processes that require heat input. Photosynthesis is also endothermic as it involves the absorption of light energy to produce glucose from carbon dioxide and water.