Which part of the world has a high diversity of organisms?

In the equation $S = CA^z$,where $S =$ species richness,$A =$ area,$Z =$ slope of the line,and $C =$ $Y$-intercept. If area is on the $X$-axis and species richness is on the $Y$-axis,what will the graph of $S = CA^z$ look like?

Where is $70\%$ of the world's total freshwater found?

Which of the following statements is correct?

The historic Convention on Biological Diversity,'The Earth Summit' was held in Rio de Janeiro in the year

Why is genetic variation important in the plant Rauwolfia vomitoria?