PATHOLOGY

Detailed explanation-1: -Internal parasites often interfere with digestion and assimilation of food, causing poor growth, temporary or permanent injuries, or death. Both external and internal parasites may weaken an animal’s immune system and create conditions favorable to bacterial disease. In severe cases, these diseases can also be deadly.

Detailed explanation-2: -Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life.

Detailed explanation-3: -Head louse living on the human scalp as well as laying eggs on human hair is a parasite in true sense. Female mosquito is not considered a parasite, as it needs human blood only for reproduction. Cuckoo that lays eggs in crow’s nest is a brood parasite not a parasite in true sense.