Sindh Zoology 2021 — Solved MCQs

Question 1

The process of removal of metabolic wastes is called:

Accepted Answer

B. Excretion — B) Excretion:Excretion is the process of removing metabolic wastes and excess substances from the body. This is the correct answer, as it specifically refers to the removal of waste products.

Question 2

Skeleton is totally absent in:

Accepted Answer

C. Amoeba — C) Amoeba: Amoebas are single-celled organisms that do not have a skeleton.Amoebas are single-celled organisms that do not have a skeleton. They are able to change shape and move without the need for a rigid structural system, making a skeleton unnecessary.

Question 3

Kidney stone or calculi are 70% composed of:

Accepted Answer

C. Calcium oxalate — The correct answer is C) calcium oxalate.Kidney stones, also known as renal calculi, are small, hard mineral deposits that form inside the kidneys when there is an imbalance of water, salts, and other substances in the urine. Calcium oxalate is the most common component of kidney stones, making up about 70-80% of all cases. This is because oxalate is a naturally occurring compound found in many foods, and calcium is a common mineral in the body. When these two substances combine in the urine, they can form a hard, crystalline stone

Question 4

It is not endocrine gland:

Accepted Answer

B. Spleen — B) Spleen:The spleen is not an endocrine gland, but rather an organ that filters the blood, stores red blood cells, and plays a role in the immune system. It does not produce hormones, making it a potential correct answer.

Question 5

A clone exactly resemble with:

Accepted Answer

C. Diploid nucleus donor — The correct answer is C) diploid nucleus donor.A clone is an exact genetic replica of an organism, produced through artificial means such as somatic cell nuclear transfer (SCNT) or DNA cloning. In cloning, the nucleus from a diploid cell (containing a complete set of chromosomes) is transferred into an enucleated egg cell, which then develops into an organism that is genetically identical to the diploid nucleus donor

Question 6

Lemark's theory based on following points except:

Accepted Answer

C. Natural selection — C) Natural selection:Lamarck's theory does not involve the concept of natural selection, which was later introduced by Charles Darwin. Natural selection suggests that organisms with favorable traits are more likely to survive and reproduce.

Question 7

The egg of hen is laid at the stage

Accepted Answer

D. Blastula — D) Blastula:The blastula stage is a phase of embryonic development where the embryo consists of a hollow ball of cells (blastoderm) surrounding a fluid-filled cavity (blastocoel). This stage occurs just before the egg is laid, making it the correct answer.

Question 8

The concentration of oxygen in atmosphere is about

Accepted Answer

A. 21% — A) 21%:The concentration of oxygen in the atmosphere is approximately 21%, making up a significant portion of the air we breathe. This is the correct answer, as oxygen makes up about 20.95% of the Earth's atmosphere..Correct answer: A) 21%

Question 9

The non-coding sequence of gene are:

Accepted Answer

C. Intron — C) Intron:An intron is a non-coding region of a gene that is transcribed into RNA but removed during splicing, leaving the exons to form the final mRNA sequence. Introns are non-coding sequences, making this the correct answer.

Question 10

About 180 litres fluid is filtered by the kidney everyday, 1.2 litres is excreted in urine while remaining 178.8 litres

Accepted Answer

B. réabsorbed into the blood — B) Reabsorbed in blood:The majority of the filtered fluid (178.8 litres) is reabsorbed into the bloodstream through the renal tubules, making this the correct answer. This process helps maintain fluid balance and regulate electrolyte levels.

Question 11

Each myosin filament is surrounded by:

Accepted Answer

D. 6 actin filaments — D) 6 actin filaments: Each myosin filament is surrounded by 6 actin filaments, which are arranged in a hexagonal pattern. This is the correct answer, as the hexagonal arrangement of actin filaments around each myosin filament is a key feature of muscle cell structure.

Question 12

Goitre is caused by the lack of:

Accepted Answer

A. Iodine — A) Iodine:Iodine deficiency is a common cause of goiter, as iodine is essential for the production of thyroid hormones. Without sufficient iodine, the thyroid gland may become enlarged, leading to goiter.Correct answer: A) Iodine

Question 13

The early division of fertilized egg is called:"

Accepted Answer

B. cleavage — B) Cleavage:Cleavage is the early division of the fertilized egg, characterized by rapid cell division without significant growth. It's the correct answer, as it refers to the initial division process.

Question 14

These are spindle shaped uninucleated muscles:

Accepted Answer

A. smooth muscle — A) Smooth:Smooth muscles are spindle-shaped and uninucleated, meaning they have a single nucleus. They are found in the walls of hollow organs, such as the digestive tract, blood vessels, and airways. They are responsible for involuntary movements, like contractions to move food through the digestive system.

Question 15

Hermaphrodite is the term used for:

Accepted Answer

C. Bisexual animals — C) Bisexual animals:Bisexual animals, also known as hermaphrodites, are those that have both male and female reproductive organs in the same individual. This term is used to describe animals that can produce both sperm and eggs.

Question 16

It is controlled by medulla oblongata in the brain:

Accepted Answer

B. breathing — B) Breathing:Breathing is controlled by the medulla oblongata, which regulates the rate and depth of breathing. It sends signals to the diaphragm and other muscles involved in respiration to breathe automatically.

Question 17

The enzyme used to seal the DNA is:

Accepted Answer

C. Ligase enzyme — C) Ligase enzyme:DNA ligase seals gaps between adjacent DNA fragments, forming a continuous strand. It's the correct answer, as it "stitches" DNA fragments together.

Question 18

Multifactorial defects include:

Accepted Answer

B. many genes and environmental factors — B) Many genes and environmental factors:Multifactorial defects are caused by a combination of multiple genetic and environmental factors, interacting together to produce a particular trait or disorder. This is the correct answer.

Question 19

This bone is not present in the lipids

Accepted Answer

A. Tibis

Question 20

This gas is responsible for globał warming

Accepted Answer

C. Carbon Dioxide — C) Carbon dioxide:Carbon dioxide (CO2) is a greenhouse gas that traps heat in the atmosphere, contributing significantly to global warming. Human activities like burning fossil fuels and deforestation have increased CO2 levels, leading to a global average temperature increase.

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