Identify the correct statements from the following:
A. In amensalism, both species involved benefit from the interaction.
B. Cattle egrets and grazing cattle exhibit a commensal relationship.
C. Ectoparasites live inside the host’s body, causing harm to the host.
D. Cuscuta growing on hedge plants is an example of ectoparasitism.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → B and D are correct.
False. A. In amensalism, both species involved benefit from the interaction. In amensalism one species is harmed and the other is unaffected (–, 0). Both benefit only in mutualism.
True. B. Cattle egrets and grazing cattle exhibit a commensal relationship. Moving cattle stir up insects that the egrets catch. The egrets gain and the cattle are neither harmed nor helped: a classic case of commensalism.
False. C. Ectoparasites live inside the host’s body, causing harm to the host. Ectoparasites feed on the external surface of the host, like lice on humans and ticks on dogs. Parasites living inside the host are endoparasites.
True. D. Cuscuta growing on hedge plants is an example of ectoparasitism. Cuscuta has lost its chlorophyll and leaves and draws food from the host plant from the outside, so it is an ectoparasite.
Statements B and D are correct.
NCERT Extract:
Population Interactions – “… Both the species benefit in mutualism and both lose in competition in their interactions with each other. In both parasitism and predation only one species benefits (parasite and predator, respectively) and the interaction is detrimental to the other species (host and prey, respectively). The interaction where one species is benefitted and the other is neither benefitted nor harmed is called commensalism. In amensalism on the other hand one species is harmed whereas the other is unaffected.”
Population Interactions – “Parasites that feed on the external surface of the host organism are called ectoparasites. The most familiar examples of this group are the lice on humans and ticks on dogs. Many marine fish are infested with ectoparasitic copepods. Cuscuta, a parasitic plant that is commonly found growing on hedge plants, has lost its chlorophyll and leaves in the course of evolution.”
Population Interactions – “… The cattle egret and grazing cattle in close association, a sight you are most likely to catch if you live in farmed rural areas, is a classic example of commensalism.”