Target Exam

CUET

Subject

Biology

Chapter

Biodiversity and Conservation

Question:

Read the passage carefully and answer the questions based on the passage:

Species diversity on earth is not uniformly distributed. It is generally highest in the tropics and decreases towards the poles.Earth's fossil history reveals the incidences of mass extinctions in the past. Earth's rich biodiversity is vital for the very survival of mankind. It is believed that communities with high diversity tend to be less variable and more productive. The reasons of conserving biodiversity are narrowly utilitarian, broadly utilitarian and ethical. Biodiversity conservation may be in situ as well as ex-situ.

Which of the following might not account for the greater biological diversity in the tropic region?

Options:

Frequent glaciations in the past

More solar energy available

Less seasonal and more constant and predictable

Undisturbed for million of years

Correct Answer:

Frequent glaciations in the past

Explanation:

The correct answer is Option (1) → Frequent glaciations in the past

Ecologists and evolutionary biologists have proposed various hypotheses; some important ones are:

  • Speciation is generally a function of time, unlike temperate regions subjected to frequent glaciations in the past, tropical latitudes have remained relatively undisturbed for millions of years and thus, had a long evolutionary time for species diversification,
  • Tropical environments, unlike temperate ones, are less seasonal, relatively more constant and predictable. Such constant environments promote niche specialisation and lead to a greater species diversity.
  • There is more solar energy available in the tropics, which contributes to higher productivity; this in turn might contribute indirectly to greater diversity.