Question

Select the incorrect statement.

• A. Species diversity increases as we move away from the equator towards the poles.
• B. Stellar's sea cow and passenger pigeon got extinct due to over exploitation by man.
• C. Lantana and Eichhornia are invasive weed species in India.
• D. Among animals, insects are the most species-rich taxonomic group.

Answer 1

Answer: (A)

Species diversity declines with increasing distance from the equator as one move towards either north or south that is latitudinal gradient. The tropics (23.5°N to 23.5°S) are very rich in species diversity. Polar regions have very small number of species (biodiversity) because polar regions face frequent glaciations and are less seasonal and non-predictable which doesn’t promote niche specialisation. In tropics, the amount of solar energy available is more, which in turn leads to higher productivity. In temperate areas, harsh conditions occur only during winter, but in poles such conditions prevail throughout the year and few resources to support species.