Question

Paramecium reproduces by
A. Binary fission
B. Transverse fission
C. Elongated fission
D. All of the above

Answer 1

Hint: Paramecium is a unicellular organism that looks like the sole of the shoe. The size ranges from 50 to 300 micrometres and it varies from species to species. It is single-celled eukaryotes that belong to the kingdom Protista and the genus of ciliate protozoa. It reproduces asexually.

Complete answer: Paramecium mostly reproduces asexually by binary fission which means that one cell splits into two daughter cells. Binary fission occurs when necessary nutrients are available. Under appropriate conditions, they divide more than three times per day. The size of the paramecium population can grow rapidly by this type of reproduction.
a) Transverse fission: The asexual reproduction of Paramecium is in the form of transverse binary fission. Via mitosis, the paramecium micronucleus divides, while the larger nucleus divides via amitosis. Here, by mitosis, the genetic material in the nucleus (micronucleus) separates.
b) Elongated fission: Under favourable conditions, Paramecium reproduces asexually by elongated fission in the following stages:
(i) Paramecium ceases feeding and begins to repeat its DNA.
(ii) Oral groove disappears. The mitotic spindle is formed by the micronucleus and begins the mitotic division. The macronucleus changes its form and the amitotic break begins.
(iii) Both mitosis and amitosis appear to be divided into two micronuclei and macronuclei of the daughter. As the cell becomes elongated, new oral grooves form.
(iv) In the centre of the cell, the endoplasm is transversely split into two. The anterior part is known as procter, and the opiate is known as the posterior portion. In scale, form, and structure, the procter and opiate parts are just like that of their parents.
(v) Completes the entire process. A clone is known to all those individuals who are created from a single parent. It requires twenty minutes for one binary fission and it splits two or three times in 24 hours.
Hence, the correct answer is option D.

Note: Like other ciliates, Paramecium normally reproduces by dividing into two, producing two almost identical individuals from one organism. Most ciliates break transversely, splitting into two by pinching off at the centre of the long axis of the organism. By mitosis, the macronucleus does not split; instead, it enlarges and then divides into two, going to each of the new daughter cells for about half.