Assertion (A):	Sharks are said to be ammonotelic animals.
Reason (R):	Sharks can retain considerable amounts of ammonia in their blood.

 

1.	Both (A) and (R) are True and (R) is the correct explanation of (A).
2.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
3.	(A) is True but (R) is False.
4.	(A) is False and (R) is False.

Assertion   :       Aquatic mammals like whales and seals are said to be ureotelic animals.

Reason      :       It is because of the fact that their main nitrogenous waste product is urea.

Assertion   :       Death ensues if waste products are not removed from the body.

Reason      :       Excretory system removes the nitrogenous waste products from the body.

Assertion   :       Renal threshold of glucose is said to be 180 mg per 100 ml.

Reason      :       Glucose starts appearing in the urine when its blood level exceed 180 mg per 100 ml of blood.

Assertion   :       Earthworms excrete both ammonia and urea.

Reason      :       Excretion in earthworm depends on the environment.

Assertion   :       If human urine is allowed to stand for some time, it smells strongly of ammonia.

Reason      :       Main constituent of human urine is Ammonia.

Assertion   :       Birds can considerably reduce water loss in the urine.

Reason      :       Birds store urine along with faeces in the cloaca.

Assertion   :       The glomerular filtrate resembles the protein free plasma in composition and osmotic pressure.

Reason      :       The glomerular capillary wall and inner membrance of Bowman’s capsule are impermeable to large molecules.

Assertion             :       Kidneys maintain the osmotic concentration of the blood.

Reason      :       Kidneys eliminate either hypotonic or hypertonic urine according to the need of the body.