Which region shows a very high level of species richness?

The Rivet Popper hypothesis assumes the $A$ to be an aeroplane and the $B$ to be the rivets,joining all parts together. Here,$A$ and $B$ refer to:

The variation shown by the medicinal plant $Rauwolfia \text{ } vomitoria$ growing in different Himalayan ranges represents:

What is the full form of $IUCN$?

How many countries pledged their commitment to achieve a reduced rate of biodiversity loss by $2010$ in the World Summit on Sustainable Development held in $2002$ in Johannesburg,South Africa?

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.