(a) Write how parasites have evolved with adaptation to coexist with their hosts in an ecosystem. (b) Parasites are host specific and tend to co-evolve. How would the parasite respond if the host evolves a certain mechanism to resist or reject the parasite ?

Assertion : Virus is an obligate parasite. Reason : Virus is host specific.

Explain co-evolution with reference to parasites and their hosts. Mention any four special adaptive features evolved in parasites for their parasitic· mode of life.

While living in and on the host species, the animal parasite has evolved certain adaptations. Describe these adaptations with examples.

List any two adaptive features evolved in parasites enabling them to live successfully on their hosts .

Read the following statements and select the correct option. Statement 1: Brood parasitism in birds is an example of parasitism in which the parasitic bird lays its eggs in the nest of its host and the host incubates them. Statement : During the course of evolution, the eggs of the parasite bird have evolved to resemble the host's eggs in size and colour to reduce the chances of the host bird detecting the foreign eggs and removing them from the nest.

Which of the following statements is/are incorrect ? (i) The liver fluke, a parasite, depends on intermediate hosts (a snail) to complete its life cycle. (ii) The malarial parasite needs a vector (mosquito) to spread to other host organisms. (iii) In case of brood parasitism, the eggs of parasitic birds are not detected and removed from the nest because the parasite's eggs resemble the host's eggs in morphology and colour. (iv) A population of frogs protected from all predators would increase indefinitely.

A partial parasite is the one which (a) Absorbs water and mineral salts from host (b) Absorbs only water from host (c) Takes food from host only occasionally (d) Lives on the host for space only

Itchmite is connected with scabies as (a) Pathogen (b) Vector (c) Parasite (d) Intermediate host

(a) State what happens in the human body when malarial parasites infected RBCs burst to release the parasites in the blood. (b) Mention the specific sites in the host body where production of (i) sporozoites and (ii) gametocytes take place in the life cycle of the malarial parasites.

Name the host and the site where the following occur in the life cycle of a malarial parasite : (a) Formation of gametocytes. (b) Fusion of gametocytes.