Read the given paragraph and answer the given question :
Parasitism has evolved in many taxonomic groups from plants to higher vertebrates. Many parasites have evolved to be host specific in such a way that both host and the parasite tend to co-evolve. In accordance with their life styles, parasite evolve special adaptations and complex life cycle.
Complex life cycle of parasites mean:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Having one or two intermediate hosts to facilitate parasitisation of its primary host
Option (1) Having only one intermediate host — Incorrect. It is too narrow: many parasites need two intermediate hosts, such as the liver fluke.
Option (2) Having special adaptations to cling on to the host — Incorrect. Suckers and hooks are structural adaptations of parasites, not their life cycle.
Option (3) Having many hosts — Incorrect. Many parasites are in fact host-specific; the complex cycle is about intermediate hosts or vectors leading to one primary host.
Option (4) Having one or two intermediate hosts to facilitate parasitisation of its primary host — Correct. The malarial parasite, for example, needs a mosquito to reach new hosts.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.
NCERT Extract:
Population Interactions – “… In accordance with their life styles, parasites evolved special adaptations such as the loss of unnecessary sense organs, presence of adhesive organs or suckers to cling on to the host, loss of digestive system and high reproductive capacity. The life cycles of parasites are often complex, involving one or two intermediate hosts or vectors to facilitate parasitisation of its primary host.”