A group of natural populations that are reproductively isolated from other such groups and which interbreed or could interbreed with each other is called a...
a. biological genus.
b. natural family.
c. biological species
d. biological phylum.
c. biological species
The correct answer is c. biological species.
To arrive at this answer, we need to understand the concept of reproductive isolation and interbreeding. A biological species is defined as a group of living organisms that can interbreed with each other and produce fertile offspring, and are reproductively isolated from other groups. Reproductive isolation means that members of different species are unable to mate successfully with each other or produce viable offspring.
In this case, the group of natural populations mentioned is reproductively isolated from other groups, meaning they are unable to mate successfully or produce viable offspring with individuals from other groups. However, they can interbreed among themselves or have the potential to do so. This characteristic fits the definition of a biological species.
Therefore, the correct answer is c. biological species.