How many biodiversity hotspots are there in the world?

Who explained the species-area relationship?

Which of the following is true for species diversity?

Paul Ehrlich,by the Rivet Popper hypothesis,has explained:

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

Given below are two statements.
Statement-$I$: Genetic diversity is the diversity in the number and type of genes as well as chromosomes present in the same species and variations in the genes and their alleles.
Statement-$II$: Species diversity deals with the variety of species as well as the number of individuals of different species observed in an area.
In light of the above statements,select the correct answer from the options given below.