question_answer

(i) Explain the kind of interaction found between cuckoo (koel) and the crow,

(ii) Differentiate between commensalism and amensalism.

Answer:

(i) Brood parasitism is a type of parasitic interaction existing between cuckoo and the crow. In this interaction the cuckoo (parasite) lays its eggs in the nest of crow (host) for the latter to incubate them.
The eggs of parasitic birds have evolved to resemble the host?s eggs to reduce the chances of host bird from detecting and ejecting the parasitic eggs from nest.
This can be observed during the brooding (egg laying) season, i.e. from spring to summer when cuckoo has to lay its eggs.
(ii) Differences between commensalism and amensalism are as follows
Commensalism	Amensalism
An association between two organisms in which only one organism is benefitted. The other is neither harmed nor benefitted.	An association involving two organisms where one species is harmed while the other remain unaffected.
The contact between the two organisms may be periodic or continuous. However, the anemone does not derive any benefit from clown fish.	The contact is inhibitory achieved through secretion of allochemical.
For example, sea anemone with stinging tentacles and clown fish which live among them. The fish gets protection from predators due to stinging tentacles.	For example, Penicillium, a mould secretes penicillin which inhibits the growth of Staphylococcus bacterium.