Which of the following is known as the 'Lungs of the Planet'?

The term 'Alpha diversity' refers to

Select the incorrect statement regarding the plant $Rauwolfia$ $vomitoria$.

Identify the correct statements :
$1.$ According to $\text{IUCN} (2004)$,the total number of described species is slightly more than $1.5$ million.
$2.$ Robert May estimated the total species diversity on Earth to be around $7$ billion.
$3.$ Insects make up more than $70 \%$ of all recorded animal species.
$4.$ India,with $2.4 \%$ of the world's land area,contributes $8.1 \%$ to global species diversity.

What is $\beta$ (beta) diversity?

There are $..........$ species of orchids on Earth.