Which of the following nitrogenous wastes is most toxic form and requires a lot of water for removal?

1.Ammonia

2.Urea

3.Uric acid

4.Creatinine

Assertion   :       Hemodialysis can save and prolong the life of uremic patients.

Reason      :       Waste products like urea can be removed from the blood by the process of hemodialysis.

Which of the following nitrogenous wastes is least toxic?

1.Uric Acid

2.Urea

3.Creatinine

4.Ammonia

Assertion   :       Birds drink very little water and insects never consume water.

Reason      :       Birds and insects are uricotelic with negligible water requirement to eliminate nitrogenous waste.

Assertion  :       In the descending limb of loop of Henle, the urine is hypertonic, while in ascending limb of loop of Henle, the urine is Hypotonic.

Reason     :      Descending limb is impermeable to Na⁺, while ascending limb is impermeable to H₂O.

Ammonotelic organisms are not

1.Bony Fishes

2.Aquatic Amphibians

3.Aquatic Insects

4.Marine fishes

Assertion   :       In birds and reptiles, main excretory product is the combined form of urine and faeces.

Reason      :       Birds and reptiles have no separate chamber for excretion of urine and faeces.

Ammonotelic organisms excrete out

1.Ammonia

2.Ammonium ions

3.Ammonium sulfate

4.Ammonium nitrate

Assertion :       The antidiuretic hormone increases the water permeability of distal convoluted tubule.

Reason    :       In absence of ADH, water re-absorption is considerably reduced.