Question

Parasites, that feed on external surface of the host organism are called ...................

• A. Endo parasites
• B. Brood parasites
• C. Ecto parasites
• D. Commens parasites

Hint:

Anatomical prefixes for parasites:
"Ecto-" = External Outside (Ectoparasite: lice, ticks, fleas, leeches).
"Endo-" = Internal Inside (Endoparasite: tapeworms, roundworms, malaria parasite).

Answer 1

The Correct Option is C

Concept:
Parasitism is an interspecific interaction (+, -) where one organism (the parasite) obtains nourishment and shelter by living on or inside another living organism (the host), typically compromising the host's fitness without causing immediate death.
Parasites are classified based on their anatomical location relative to the host's body.

Step 1: Classification of Parasites by Location and Mode:
1. Ectoparasites: Parasitic organisms that attach to, reside on, and feed upon the external surface (skin, hair, feathers, gills) of the host organism. Common examples include human head lice (Pediculus humanus), ticks (Ixodes spp.) on dogs, marine copepods on fish, and the stem holoparasite Cuscuta (dodder) growing over host foliage.
2. Endoparasites: Organisms that live internally within host tissues, blood vessels, or lumen organs (e.g., Plasmodium inside liver cells and erythrocytes, Ascaris lumbricoides inside human intestines, and liver flukes inside the bile duct).
3. Brood Parasites: A specialized avian reproductive strategy where the parasite deposits eggs in the nest of another bird species, leaving parental care and incubation entirely to the host (e.g., the Asian Koel laying eggs in a Crow's nest).
4. Commensalism: A non-parasitic symbiotic relationship (+, 0) where the commensal benefits while the host remains unaffected.

Step 2: Matching with the Question Statement:
The question asks for parasites that feed on the external surface of the host organism.
By biological definition, these organisms are termed ectoparasites.
Final Answer:
Parasites feeding on the external surface of the host are ectoparasites, corresponding to option (C).