What does '$W$' represent in the given figure?

Identify the incorrect statement.
$I$. Speciation is generally a function of time.
$II$. Tropical environment is less seasonal,relatively more constant and predictable.
$III$. Solar energy contributes to high productivity.
$IV$. Temperate regions have remained relatively undisturbed for millions of years.

Why are coral reefs not found in the regions from West Bengal to Andhra Pradesh,but are found in Tamil Nadu and on the east coast of India?

Read the following statements:
$I.$ Species diversity increases as we move away from the equator towards the poles.
$II.$ Stellar's sea cow and passenger pigeon got extinct due to overexploitation by man.
$III.$ Lantana and Eichhornia are invasive weed in India.
$IV.$ The historic convention on biological diversity was held in $1992.$
Choose the option containing correct statements.

Identify $X, Y$ and $Z$ from the given pie charts representing global biodiversity of invertebrates and vertebrates:

What does '$X$' represent in the given graph?