Question

Which one is parasite in the true sense?
A. Head lice living on human scalp as well as laying eggs on human hair
B. Cuckoo laying eggs in crow’s nest
C. Female Anopheles biting and sucking blood from humans
D. Human fetus inside uterus and drawing nourishment from mother

Answer 1

Hint:-A true parasite takes nutrition from the host and survives on it for a longer time. Head lice suck blood from the human head and harm the hair scalps. Cuckoo bird is a brood parasite. Female anopheles is a vector. Human fetus lives in the mother host only for a developing period.

Complete Answer:-
Various organisms interact with each other in order to maintain the ecological balance in the environment. Interactions such as parasite and predation in which one organism gets benefit while the other gets harmed. The parasite lives off of another organism (the host), harming it and possibly causing death. Examples of parasites are: tapeworms, fleas, and barnacles. The parasite and its host both evolve together. The parasites evolve various adaptations to its environment and use the host in ways that harm it. Hosts also develop special features to protect it from parasites.
Head lice (Pediculus humanus capitis) cause infestation in the head. It lays eggs on its head and sucks blood from the human head. Female anopheles mosquito is a vector. It is not a parasite. It does not bite humans. The human fetus does not depend on the host mother for the entire life, that's why we cannot call it a parasite and also it does not harm the host. It is present in humans in the developing stage only. Cuckoo is known as brood parasite, they lay eggs in the nest of other animals.
From the above information we have found that head lice living on the human scalp is parasite in the true sense.
Thus, the right option is A.

Note:- Plant parasites such as cuscuta (amarbel) live on the plants and take nutrition from the plants and make it dead after some time. Parasites are mainly of two types that are endo-parasite and exo-parasite. Endo parasites live on the body surface while the exo-parasites live inside the body such as malaria parasites.