Which of the following ecologists proposed the 'rivet popper' hypothesis?

Assertion : Diversity observed in the entire geographical area is called gamma diversity.
Reason : Biodiversity decreases from high altitude to low altitude.

What is the full form of $UNESCO$?

The relationship between species richness and area is described by a straight line on a logarithmic scale using which equation?

Study the following statements and select the correct option given below:
Statement-$I$: Biodiversity is the variety of features of life observed in the living organisms at different levels within a defined area.
Statement-$II$: Living organisms' attempt to accommodate with different environmental conditions forms the basis of diversity.

Select the correct statement regarding biodiversity.