How many biodiversity hot spots have been identified in the world?

Within biological communities,some species are important in determining the ability of a large number of other species to persist in the community. Such species are called

Identify the full form of $IUCN$.

Within a region,species richness increases with an increasing explored area,but only up to a limit. Which naturalist proposed this statement?

The total number of biodiversity hotspots in the world is

Where is the highest genetic diversity in agricultural crops found?