Biology - Excretory Products and their Elimination Question with Solution | TestHub
Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): Whenever water retention is necessary, pituitary secretes ADH
Reason (R): ADH makes the cells in the wall of collecting ducts impermeable to water.
In light of the above statements, choose thecorrectanswer from the options given below.
Options:
Answer:
Solution:
Assertion (A) is true because when the body fluid volume or water content is low, osmoreceptors stimulate the hypothalamus to release Antidiuretic Hormone (ADH) from the neurohypophysis (posterior pituitary) to prevent diuresis and retain water.
Reason (R) is false because ADH facilitates water reabsorption from the latter parts of the tubule (distal convoluted tubule and collecting duct) by making the cells in their walls permeable to water, not impermeable. It does this by inserting aquaporin channels into the cell membranes.
Therefore, (A) is true but (R) is false.
Answer: (A) is true but (R) is false.
