Modes of Excretion — NEET Biology MCQs with Solutions
Free NEET Biology Modes of Excretion MCQs with step-by-step solutions (6 questions). Part of Excretory Products and Their Elimination. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Modes of Excretion · easy · theory
Animals that excrete nitrogenous waste mainly as ammonia are called:
A. Uricotelic
B. Guanotelic
C. Ureotelic
D. Ammonotelic ✓ Correct
Solution: Ammonotelic animals (most aquatic animals) excrete ammonia, which is highly soluble and toxic but easily diluted.
Q2 — Modes of Excretion · easy · theory
Mammals, including humans, are ______ because they mainly excrete:
A. Ureotelic; urea ✓ Correct
B. Uricotelic; urea
C. Uricotelic; uric acid
D. Ammonotelic; ammonia
Solution: Mammals convert toxic ammonia to less toxic urea (ureotelism), excreted by the kidneys.
Q3 — Modes of Excretion · medium · theory
Birds and reptiles are uricotelic, excreting uric acid, which is advantageous because it:
A. Is highly toxic and soluble
B. Requires very little water for excretion (conserves water) ✓ Correct
C. Cannot be stored
D. Needs a lot of water
Solution: Uric acid is nearly insoluble and can be excreted as a semi-solid paste, conserving water — useful for terrestrial/egg-laying life.
Q4 — Modes of Excretion · medium · theory
Ammonia is the most toxic nitrogenous waste and needs large amounts of water because it:
A. Requires no water
B. Is insoluble
C. Is a solid
D. Is highly soluble and must be diluted for excretion ✓ Correct
Solution: Ammonia is very soluble and toxic, so ammonotelic animals need plenty of water to flush it out.
Q5 — Modes of Excretion · hard · theory
Match the animal to its excretory product: Bony fish, Frog (adult), Bird —
A. Ammonia, Urea, Uric acid ✓ Correct
B. Ammonia, Uric acid, Urea
C. Uric acid, Urea, Ammonia
D. Urea, Ammonia, Uric acid
Solution: Bony fishes are ammonotelic, terrestrial adult amphibians (frogs) ureotelic, birds/reptiles uricotelic.
Q6 — Modes of Excretion · hard · theory
The conversion of ammonia to urea in mammals occurs primarily in the ______ via the ______:
A. Liver; ornithine (urea) cycle ✓ Correct
B. Liver; Calvin cycle
C. Kidney; Krebs cycle
D. Kidney; ornithine cycle
Solution: Urea is synthesised in the liver by the ornithine cycle and then carried to the kidneys for excretion.