Looking for classes? Ksquare Career Institute, Bengaluru →
Earthworms are -
A
Ureotelic when plenty of water is available
B
Uricotelic when plenty of water is available
C
Uricotelic under conditions of water scarcity
D
Ammonotelic when plenty of water is available
Detailed Solution
The nature of the nitrogenous waste excreted by an animal depends on the availability of water.
Ammonia is highly toxic and needs a large amount of water for its removal, so it is excreted when water is plentiful.
Earthworms live in moist soil. When plenty of water is available, they excrete mainly ammonia, i.e. they are ammonotelic.
When water is scarce, in drier conditions, they change over to excreting mainly urea, i.e. they become ureotelic, since urea is less toxic and needs less water.
They are not uricotelic under either condition.
So earthworms are ammonotelic when plenty of water is available.
Ammonia is highly toxic and needs a large amount of water for its removal, so it is excreted when water is plentiful.
Earthworms live in moist soil. When plenty of water is available, they excrete mainly ammonia, i.e. they are ammonotelic.
When water is scarce, in drier conditions, they change over to excreting mainly urea, i.e. they become ureotelic, since urea is less toxic and needs less water.
They are not uricotelic under either condition.
So earthworms are ammonotelic when plenty of water is available.