Biotechnology and its Applications — BIOLOGY STD 12 Science — Question

How would the gene flow or genetic drift affect the population in which either of them happen to take place?

In view of the current food crisis, it is said, that we need another green revolution. Highlight the major limitations of the earlier green revolution.

Protein synthesis machinery revolves around RNA but in the course of evolution it was replaced by DNA. Justify.

1. Explain the property that prevents normal cells from becoming cancerous.
2. All normal cells have inherent characteristic of becoming cancerous. Explain.

How does zona pellucida of ovum help in preventing polyspermy?

Write the biological (binomial) name of causal organism of the following disease:
Elephantiatis (Filariasis).

Due to uncontrolled excessive hunting, the population of tiger in a forest becomes zero. Discuss the long-term effects of this situation in the population of deer in that forest.

What was the composition of the primitive atmosphere that favoured abiotic origin of life on earth?

Mark the odd one in each series.

1. Scrotum, rete testis, Fallopian tube, vas deferens.
2. Ovary, uterus, vagina, ejaculatory duct.
3. Prostate, testis, seminal vesicles, Cowper's gland.
4. Fallopian tubes, vagina, uterus, ovaries.

What are germ pores?