Punjab Biology 2021 Paper 1 — Solved MCQs

Question 1

The excretory product that requires minimum water for its elimination as compared to others is:

Accepted Answer

A. Uric acid — Ammonia, urea and uric acid are the major forms of nitrogenous wastes excreted by the animals. Ammonia is the most toxic form and requires large amount of water for its elimination, whereas uric acid, being the least toxic, can be removed with a minimum loss of water.

Question 2

Which of the following is called as Excretophore?

Accepted Answer

C. Leaf — Plants can get rid of excess water by transpiration and guttation. It has been shown that the leaf acts as an 'excretophore' and, in addition to being a primary organ of photosynthesis, is also used as a method of excreting toxic wastes via diffusion.

Question 3

Which of the following cells lack of secondary walls?

Accepted Answer

B. Collenchyma — Collenchyma tissue is composed by elongated living cells of uneven primary thick walls, which possess hemicellulose, cellulose, and pectic materials. It provides support, structure, mechanical strength, and flexibility to the petiole, leaf veins, and stem of young plants, allowing for easy bending without breakage.

Question 4

Vertebrae of neck region are called:

Accepted Answer

C. Cervical — The cervical spine (neck region) consists of seven bones (C1-C7 vertebrae), which are separated from one another by intervertebral discs.

Question 5

The meristems that are found at the tips of roots and shoots are called:

Accepted Answer

D. Apical meristems — The apical meristem, also known as the “growing tip,” is an undifferentiated meristematic tissue found in the buds and growing tips of roots in plants. Its main function is to trigger the growth of new cells in young seedlings at the tips of roots and shoots and forming buds.

Question 6

In Microcephaly, the individuals are born with small:

Accepted Answer

A. Skull — Microcephaly is a birth defect where a baby's head is smaller than expected when compared to babies of the same sex and age. Babies with microcephaly often have smaller brains that might not have developed properly.

Question 7

Crossing over is occurred in:

Accepted Answer

B. Pachytene — In pachytene the pairing of homologous chromosomes is completed. Chromosomes become more and more thick. Each bivalent has four chromatids, which wrap around each other. Non-sister chromatids of homologous chromosomes exchange their segments due to chiasmata formation, during the process called crossing over. In this way reshufling of genetic material occurs which produces recombination.

Question 8

Down's syndrome has number of chromosomes:

Accepted Answer

A. 47 — Down syndrome is a genetic condition where a person is born with an extra copy of chromosome 21. This means that they have a total of 47 chromosomes instead of 46. This can affect how their brain and body develop. People diagnosed with Down syndrome have happy and healthy lives with supportive care.

Question 9

The receptors which produce the sensation of pain are called:

Accepted Answer

C. Nociceptors — The pain receptors are nociceptors. They are known to exist in muscle, joints, and skin.

Question 10

Parthenocarpy is artificially induced by adding:

Accepted Answer

A. Auxins — Induction of Parthenocarpic Fruit by Hormone Application. Auxin was the first hormone reported to induce parthenocarpy in plants. Auxin analogues induce parthenocarpy in Cucurbitaceae crops such as watermelon, cucumber, and zucchini (C. pepo L.), resulting in seedless fruit formation

Question 11

Highly condensed portion of chromatin are called:

Accepted Answer

D. Heterochromatin — Chromatin exists in two forms. One form, called euchromatin, is less condensed and can be transcribed. The second form, called heterochromatin, is highly condensed and is typically not transcribed. Under the microscope in its extended form, chromatin looks like beads on a string. The beads are called nucleosomes.

Question 12

Position of gene on chromosome is called:

Accepted Answer

C. Locus — Locus is the physical position a gene or a factor occupies on the chromosome.

Question 13

The enzyme which is used to cut out the gene of interest, is called:

Accepted Answer

B. Restriction Endonucleases — Restriction enzymes, also called restriction endonucleases, recognize a specific sequence of nucleotides in double stranded DNA and cut the DNA at a specific location. They are indispensable to the isolation of genes and the construction of cloned DNA molecules.

Question 14

Archaeobacteria can tolerate temperature upto:

Accepted Answer

A. 120℃ — A group of bacteria, called archaebacteria that tolerate temperatures up to 120°C.

Question 15

The actual location of place, where an organism lives is called its:

Accepted Answer

D. Habitat — A habitat is a place where an organism makes its home. A habitat meets all the environmental conditions an organism needs to survive. For an animal, that means everything it needs to find and gather food, select a mate, and successfully reproduce.

Question 16

In aquatic ecosystem near shore zone is called:

Accepted Answer

C. Littoral zone — The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore.

Question 17

A treasure of all types of resources essential to maintain life on earth is:

Accepted Answer

A. Environment — Environment is a treasure of all types of resources essential to maintain life on earth. It is direct and indirect source of food and shelter to everyone.

Punjab Biology 2021 Paper 1 — Solved Past Paper with Answers

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