Question

Name the type of cell division observed in foetal cells and the mega nucleus of Paramecium.

Answer 1

Hint: In Paramecium, meiosis is observed in foetal cell and amitosis is seen in the meganucleus. Meiosis is a reduction division, in which the daughter cell contains half the number of chromosomes as of parent. Amitosis is known as the direct method of cell division, characterized by simple division of the nucleus without the formation of chromosomes.

Complete answer:
Paramecium can reproduce asexually by binary fission. During binary fission, the paramecium cell divides into two genetically identical daughter cells or offspring. It was identified that the foetal cells undergo meiosis, but the mega nucleus divides another way, called an amitotic, or non-mitotic, mechanism. "It is exactly not based on mitosis but actually it divides between the two daughter cells and somehow is able to keep approximately the same number of copies of each gene.

Additional information:
Paramecia have two kinds of nuclei: a large ellipsoidal nucleus called a macronucleus and a small nucleus called a micronucleus. Both types of nuclei have full complement of genes that contain the hereditary information of the organism. The organism cannot survive in the absence of macronucleus. The macronucleus is the basic centre of all metabolic activities of the organism. The organism cannot reproduce without the micronucleus. It is a storage site for the germ-line genetic material of the organism. It gives rise to the macronucleus and is responsible for the genetic reorganization that occurs during conjugation (mode of sexual reproduction).

Note:
Paramecium is an organism with dual nuclear apparatus, having a macronucleus (polyploid), and one or more micronuclei (diploid). The macronucleus controls all non-reproductive cell functions by expressing the genes needed for daily activities. The micronucleus is considered as the germline nucleus, consisting of the genetic material that is transmitted along from one generation to another.