Question

___________ refers to a set of animals which closely resemble each other in certain marked features by descent.

Answer 1

Certain individuals from a species which closely resemble each other in certain marked features from the descent (origin) after several generations of selective mating constitute a breed.
Example is the milch breed, which is a breed of cattle mainly meant for milk production. For example, Jersey cow. Several breeds can be identified in a particular species.

Cattle is a common term used for hooved herbivorous mammals that constitute the genus Bos. Examples include cow, bull, bullock, etc.

Man domesticates a variety of animals for food, transport, agricultural operations, wool, fur, research, etc.
Certain animal species that are reared for domestic purposes constitute livestock.

Population is the number of organisms of the same species capable of interbreeding that live in a particular geographical area at the same time.