Question

In desert animals-
A. Proximal Convoluted tubules are very long.
B. Loop of Henle is very long.
C. Both of the above.
D. Distal convoluted tubules are very short.

Answer 1

Hint: Desert animals are just like desert plants. Desert plants as the name suggests are grown up in arid regions and they survive on less amount of water. Prickly pear cactus is an example of a desert plant, and we all know that cactus is the most prevalent desert plant. There are types of desert animals like- camels, kangaroos, and some desert snakes which survive and thrive in the desert.

Complete Explanation:
Option A Proximal Convoluted tubules are very long- proximal convoluted tubules that are part of nephron. Since desert animals have different adaptations in excretion. They avoid excess loss of water from the body as water is minimal in surroundings.
So, option A is not correct.
Option B Loop of Henle are very long- desert animals that do not find water easily in the atmosphere hence they are bound to conserve water. Their urine is much more concentrated. Kidneys of desert animals have longer long loops of Henle so that it can produce more concentrated urine to limit the water amount.
So, option B is correct.
Option C Both of the above- both proximal convoluted tubules and loop of Henle cannot correct as PCT are a part of nephrons which helps in excretion easier. But only the loop of Henle is long enough to prevent excess water loss.
So, option C is not correct.
Option D Distal convoluted tubules are very short- DCT and PCT are respectively parts of nephrons. They are of equal size and proportionate compared to the loop of Henle.
So, option D is not correct.

Hence, Option B is the correct answer.

Note:
Desert animals as we know have adaptations like- camels have humps at their back which store fat inside which a camel can break down into occupy water and energy when nourishment is not available. Desert animals rarely sweat so they don’t have to face water scarcity in their body. This helps in living these animals for a longer period of time. They also have large tough mouths able to eat thorny vegetation; they also get their water from these plant bodies.