Question

In which species of Paramecium, autogamy is found?

• A. Paramecium caudatum
• B. Paramecium aurelia
• C. Paramecium bursaria
• D. All of the above

Answer 1

The correct option is B Paramecium aurelia

Paramecium is a unicellular protozoan. It forms gametes by the division of single parent cell and this is known as Autogamy. It is also known as self conjugation. Paramecium generally reproduce asexually by means of binary fission or sexually by means of cross fertilisation. Sometimes, under stress conditions, Paramecium may undergo Autogamy. Autogamy is found in Paramecium aurelia which has 1 macronucleus and 2 micronuclei. The macronucleus degenerates and the two micronuclei undergo meiosis to form 8 haploid daughter nuclei. Out of these 8 haploid daughter nuclei degenerate and the remaining 1 micronucleus undergo mitosis to form 2 daughter nuclei which fuse to form a diploid nucleus, also called as synkaryon. This synkaryon divides twice to form 4 nuclei, out of which two become micronuclei and two become macronuclei. The micronuclei divides two times along with the body of cell to form two daughter cells. Each daughter cell contains 1 macronucleus and 2 micronuclei.

So ,the correct answer is B.