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JAMB Biology 1993 Question 22

Question 22

Excretion

Members of the phylum Protozoa use the contractile vacuole

  1. A.to remove excess food
  2. B.for movement
  3. C.for digestion
  4. D.to remove excess water.
Show the answer and explanation

Answer: D (to remove excess water.)

Explanation

Water keeps entering a freshwater protozoan by osmosis; the contractile vacuole collects it and pumps it out (osmoregulation).