Even if all the biodiversity hotspots are put together,they cover less than $2 \%$ of the Earth's land area.

Choose the correct matching for the Amazon rainforest biodiversity data: $a$-mammals,$b$-$1300$ species,$c$-$3000$ species,$d$-$427$ species,$e$-birds,$f$-fishes.

Tropical regions show the greatest level of species richness because:
$A$. Tropical latitudes have remained relatively undisturbed for millions of years,hence more time was available for species diversification.
$B$. Tropical environments are more seasonal.
$C$. More solar energy is available in the tropics.
$D$. Constant environments promote niche specialization.
$E$. Tropical environments are constant and predictable.
Choose the correct answer from the options given below.

If there were $50$ species of reptile present in one ecosystem,what is this called?

Provide the definitions/explanations for the following:
$(i)$ Species Diversity
$(ii)$ Endemism

Biodiversity refers to $........$