The tropical rain forest has a large population of animals. Explain why is it so.

In India, tropical rain forests occur in

[A] : The tropical rain forests are rich in biodiversity on this biosphere. [R] : The low latitude humid tropics harbour the rain forest ecosystems .

Assertion (A) : Tropical rain forests are disappearing fast from developing countries such as India. Reason ( R ) : No value is attached to these forests because these are poor in biodiversity.

Why is transport of materials necessary in a plant or in an animal? Explain.

A spherical capacitor has an inner sphere of radius 12 cm and an outer sphere of radius 13 cm. The outer sphere is earthed and the inner sphere is given a charge of 2.5 µC. The space between the concentric spheres is filled with a liquid of dielectric constant 32. (a) Determine the capacitance of the capacitor. (b) What is the potential of the inner sphere? (c) Compare the capacitance of this capacitor with that of an isolated sphere of radius 12 cm. Explain why the latter is much smaller.

Amazon rain forest has the greatest biodiversity on earth. List any two hypothese that are proposed by the biologists to account for the greater biological diversity .

Name two metals that start floating after sometime when immersed in water and explain why they do so.

In animal husbandry, if two closely related animals are mated for a few generations, it results in loss of fertility and vigour. Why is it so?