Question

Obligate parasites live on
A. Living host only
B. Living host and dead organic matter
C. Dead organic matter only
D. Artificial liquid medium

Answer 1

Hint:- In nature, all organisms interact with one another to derive their nutrition, to survive, and to reproduce. A close relationship between the individuals of the same species or different species such that at least one of the individuals is benefitted is called symbiosis. This relationship may also benefit both parties involved. It may harm one and benefit the other or just benefit one while the other is unaffected. Symbiosis can be classified into- mutualism, commensalism, parasitism, competition, and predation.

Complete Answer:-
Parasites are organisms that require another organism (host) for its survival. They latch on to this host, seek shelter, and derive nutrition from it. These parasites may reside within the host or outside the host’s body. The parasite may be a microbe or in some cases organisms such as worms, fleas, etc. Parasites can be classified as facultative or obligate.
A parasitic organism may not reside within one host during its entire life cycle. It may jump from one host to another. For example, Plasmodium is an obligate parasite found in female Anopheles mosquitoes. This mosquito acts as a vector and transfers sporozoite (an infective form of the organism) to humans. In the liver cells of humans, this sporozoite begins reproducing. Red blood cells get infected and ultimately cell lysis occurs. The human is said to be suffering from malaria.
Obligate parasites are very much dependent on their host for survival. Their host is always a living organism. They do not derive nutrition from dead organic matter or any artificial medium for its survival. In general, parasites are harmful to their host. When the host dies the parasite moves on to another host.

The correct option is (A). Obligate parasites live on living hosts only.

Note:- Both parasites and pathogens exploit their hosts. By definition, a pathogen is a disease-causing organism. While some parasites are also pathogens, not all parasites cause disease. Facultative parasites are not entirely dependent on its host for its survival. Saprophytes are organisms that derive their nutrition from dead or decaying organic matter.