I'm pretty sure the answer would be A. Chromosomes contain one or more genes.
The cytoplasm and the nucleus together are known as the protoplasm, the living matter of the cell.
Answer:
Prezygotic barriers:
1. Habitat isolation
2. Behavioral isolation
Explanation:
Pre-zygotic barriers are the barriers which do not allow the formation of the zygote in the organisms.
The two mechanisms of the pre-zygotic barriers are the:
1. Habitat isolation: the Flycatchers do not share the same habitat which is also mentioned in the question that they live on different islands.
2. The behavioural isolation: the Flycatchers could have evolved the different mating rituals as a result of which the could not interbreed.
Thus, Habitat isolation and Behavioral isolation are correct.