Question

Which of these is not a reason accounting for greater biodiversity of tropics?
A. More niche specialisation
B. Availability of more solar energy
C. More time for species diversification
D. Large seasonal variations in environmental factors

Answer 1

Hint:
Tropical regions are the regions that are near the equator and between the tropic of cancer in the northern hemisphere and the tropic of Capricorn in the southern hemisphere. This region receives direct sunlight and hence the temperature of this region is high throughout the year.

Complete answer:
Higher biodiversity is seen in the regions that are near the equator due to the warmer climate which results in relatively higher productivity. Tropical regions consist of more than two-thirds of the world's biodiversity. Biodiversity in tropical regions is higher mainly due to three reasons:
(a) The formation of new species in the course of evolution is called speciation. It is a function of time. Tropical regions have remained relatively undisturbed for millions of years, unlike temperate regions which have suffered frequent glaciations in the past, due to which tropical regions have more time for species diversification.
(b) The environment of tropical regions is less seasonal, constant and predictable, unlike temperate regions. This promotes niche specialisation and greater species diversification.
(c) Higher productivity is seen as it receives direct sunlight, which promotes greater diversity.
Thus, the correct answer is:- Large seasonal variations in environmental factors.

Option ‘D’ is correct

Note:
The diversity in species decreases as we move towards poles from the equator. India, with much of its land in the tropical region, has more than 1,200 species of birds. A forest in a tropical region like the equator has ten times more species of vascular plants as compared to a forest of an equal area in the temperate region.