Explain the adaptation in plants using cactus as an example

Which of the following typically characterizes a tropical rainforests

Agene pool: a) is the collection of all the alleles found in a single species b) is the collection of all the alleles found in a single population c) is the collection of all the chromosomes found in a single population d) is the collection of genes in a species that allow the individuals to swim

What substance acts to prevent sudden ph changes in bodily fluids?