NSO Level 1- Science Olympiad (SOF) Class 12: Questions 20 - 23 of 60

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Question number: 20

» Biology » Reproduction

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MCQ▾

Question

There are low failure rates of contraceptives Estrogens and progestins. How do they work?

Choices

Choice (4) Response

a.

Preventing implantation of blastocyst

b.

Preventing ovulation by suppressing LH surge

c.

Preventing sperm from entering uterus

d.

Preventing sperm from reaching egg

Question number: 21

» Biology » Biotechnology

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Question

In monoclonal antibody technology, mammalian cells that produce an antibody are fused with tumor cells which replicate endlessly. What will be the result of this cell fusion?

Choices

Choice (4) Response

a.

Carcinoma

b.

Lymphoblast

c.

Hybridoma

d.

Myeloma

Question number: 22

» Biology » Ecology

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Question

With regard to the biotic succession on bare rock which of the following statements is correct?

Choices

Choice (4) Response

a.

Conditions for growth of mosses are made favourable by Foliose lichens

b.

Foliose lichens e. g. Rhizocarpon follow the pioneer lichens which are usually crustose lichens e. g. Graphis

c.

Moss stage is followed by perennial grasses e. g; Cymbopogon, which finally replace annual grasses e. g; Poa

d.

All of the above

Question number: 23

» Biology » Biotechnology

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Question

For a lab experiment you are trying to insert a gene from human DNA into plasmid and there is a preparation of human DNA cut with restriction endonuclease A given to you by the professor. Your gene of interest has sites on both ends for restriction endonuclease B. Now, you have a plasmid with single site for B, but not for A. What would you do in this situation?

Choices

Choice (4) Response

a.

Plasmid cut with restriction endonuclease A and insert human DNA cut with restriction endonucelase A into plasmid.

b.

Plasmid cut with restriction endonuclease A and insert human DNA cut with restriction endonuclease B into plasmid.

c.

Plasmid cut twice with restriction endonuclease B and the two fragments are ligated onto the ends of human DNA fragments cut with restriction endonuclease A.

d.

Human DNA cut again with the restriction endocuclease B and insert these fragments into plasmid cut with the same enzyme.

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