Question

9. Give reasons:
(1) The number of stomata are more on the lower surface of the leaf as
compared to the upper surface.
(2)Aquatic animals breathe faster than the terrestrial animals.​

Answer 1

Answer:

1)Because on upper side the area is less.

2)Because they need oxygen continuously.

Answer 2

1.) There are more stomata on the lower surface of a leaf than its upper surface as it prevents excessive transpiration (water loss) while facing the sun, and at the same time maintains the optimum rate of exchange of gases.

2.) Aquatic animals have to take up O2 dissolved in water, unlike terrestrial organisms which take up O2 from atmosphere.

Since concentration of O2 is more in atmosphere than in water, aquatic organisms need to breathe faster to take in the same amount of oxygen.