Question

Read the following statements related to latitudinal gradients of biodiversity and identify the correct statement.

• A. Biodiversity remains constant with latitude
• B. Species diversity increases from the equator towards the poles
• C. Tropical regions harbour more species than temperate and polar regions
• D. Tropical regions were subjected to many glaciations in the past

Answer 1

The correct option is C Tropical regions harbour more species than temperate and polar regions

Biodiversity refers to the variations in genes and species present in different ecosystems on Earth. It is not uniform throughout the Earth and varies with change in latitude (imaginary horizontal mapping lines on the Earth's surface). It is maximum at the equator and gradually decreases as we move towards the poles.
The equatorial or tropical region receives direct sunlight, and therefore has higher temperature compared to other regions. This causes more evaporation, resulting in precipitation in the form of rain. Thus, there is a constant weather pattern in the tropics which is favourable for the growth of plants and animals.
The polar regions near the North and South poles have extremely cold climate and hence have the least biodiversity.
For example, Columbia, located near the equator, has nearly 1400 species of birds while Greenland, which is near the poles, has only 56 species. So option c is correct.

Temperate regions have been subjected to frequent glaciation in the past whereas the tropical latitudes have remained relatively undisturbed for millions of years.