Natural Selection

Q. What is genetic drift ? Give its significance in evolution.

Q. Read the given paragraph carefully:
Red-coloured beetles are living on green leaves of bushes. These beetles increase in numbers by sexual reproduction. Crows, being their predators, consume beetles and regulate their population. During reproduction, few beetles develop green colour instead of red colour. This variation in body colour gives green coloured beetles an advantage and over the years, the number of green beetles in the population will increase generation after generation.
Which of the following statements are correct regarding the given paragraph:
(i) The given paragraph depicts an example of "ontogeny recapitulates phylogeny".
(ii) Artificial selection is exerted by crows.
(iii) Natural selection is exerted by crows.
(iv) More red-coloured beetles will be eaten up.
(v) The given paragraph depicts an example of convergent evolution.

1. (i), (iv) and (v) only
2. (iii) and (iv) only
3. (i), (ii) and (iii) only
4. (ii) and (v) only

Q. The larva of Anopheles differs from Culex in which of the following aspects?

1. Their head is down ward touching the bottom of lakes, rivers, etc and has respiratory trumpet.
2. Their head is upward touching the surface of lakes, river, etc and has no respiratory trumpet.
3. The body of larva horizontal to the surface of water and has respiratory trumpet.
4. The body of larva making an angle to the surface of water and has no respiratory trumpet.