Question

Assertion: Amoeba reproduce by binary fission during unfavourable conditions
Reason: During binary fission the Amoeba withdraws its pseudopodia and forms a cyst around itself.

• A. Both assertion and reason are true and reason is the correct explanation of assertion.
• B. Both assertion and reason are true but reason is not the correct explanation of assertion.
• C. The assertion is true but reason is false.
• D. Both assertion and reason are false.

Answer 1

The correct option is D Both assertion and reason are false.

When conditions become unfavourable the amoeba uses a phenomenon called encystation. It withdraws its pseudopodia and secretes a three-layered hard covering or cyst around itself. When favourable conditions return, the encysted Amoeba divides by multiple fission or sporulation. Then the cyst wall bursts out and the spores are liberated in the surrounding medium which grow up into many Amoeba.

Therefore during unfavourable conditions Amoeba reproduce by multiple fission and during favourable conditions Amoeba reproduces by binary fission.