What are the reproductive methods of paramecia?

The paramecium is a very small, cylindrical single-celled organism made up of only one cell, and is hermaphroditic. The most common is the large paramecium, with a lifespan of about one day and night. It is called a paramecium because its body shape, viewed from a flat angle, looks like an upside-down straw sandal sole. Let us take a look below at the reproductive methods of paramecia!

Asexual reproduction

Asexual reproduction in paramecia is transverse binary fission. Transverse binary fission refers to a mode of asexual reproduction in which a single cell divides and reproduces along the transverse axis. The micronucleus first undergoes mitosis, then the macronucleus undergoes amitosis, after which the middle of the organism body constricts transversely and splits into two new individuals.

Sexual reproduction

1. In a certain environment, the oral grooves of two paramecia connect, the cell membranes fuse, and part of the genetic information in the micronuclei is exchanged, beginning conjugation.

2. The micronucleus in each individual each undergoes meiosis once, respectively forming 4 haploid micronuclei.

3. Of the 4 micronuclei in each individual, 3 disappear, and the remaining micronucleus divides into one male nucleus (smaller) and one female nucleus (larger), while the macronucleus disappears at the same time.

4. The 2 conjugated individuals exchange male nuclei and fuse them with the other's female nucleus, after which the organism bodies separate.

5. The new nucleus formed by fusion in each individual divides 3 times, each forming 8 nuclei, of which 4 form new macronuclei and 4 form new micronuclei.

6. Of the 4 new micronuclei, 3 disappear, the micronucleus and cytoplasm divide, and the macronucleus no longer divides.

7. After the micronucleus and cytoplasm divide 2 times, each individual forms 4 new individuals, producing a total of 8 new individuals.