When individual organisms of two populations can no longer mate to produce fertile offspring, the two populations are considered to be

different families
same species
different species
unrelated
du

List the advantages and disadavantages of the switch from persistent chlorinated hydrocarbon pesticides (such as ddt) to nonpersistent organophosphate pesicides. have the benefits of the switch outweighed the disadvantages? explain.

Ecology can best be described as the study of what

Which of the following explains why a tree is often used as a model to represent the principle of common descent