Question
Question: How is mitosis and meiosis different?...
How is mitosis and meiosis different?
Solution
Cell cycle involves all the changes which occur during cell growth and cell division. It is the sum of all those events by which a cell replicates its genome and synthesizes cell contents. This is of three types- amitosis, mitosis and meiosis.
Complete answer:
Mitosis is also known as somatic cell division or equational division. It involves the division of somatic cells in such a way that its chromosome number is kept constant in daughter cells equal to those in parent cells. Therefore in this, daughter cells are quantitatively as well as qualitatively similar in genetic material to the parents.
The time taken by a mitotic division may range from 30 minutes to 3 hours. It is species-specific but also depends upon the types of tissue, temperature, etc.
It occurs both in somatic cells as well as germ cells of the gonads during the multiplicative phase of gametogenesis. In plants, mitosis occurs in meristematic cells, cambial cells, etc. In humans, it occurs in stratum germinativum of skin, bone marrow, etc.
Mitotic division occurs in both haploid and diploid cells.
Whereas, meiosis is a special type of division in which the chromosomes duplicate only ones but the cell divides twice. So in this division, one parent cell produces four daughter cells. Each of the daughter cells has half the chromosome number and DNA amount then normal parental cells. Therefore meiosis is also known as reductional division.
It is reported in diploid germ cells of sex organs, for example, primary spermatocytes of the testis to form spermatozoa and primary oocytes of ovaries to form ova in animals. It also occurs in pollen mother cells of anther and megaspore size of the ovule of the ovary of flowers in the plant to form the haploid spores.
Note: It can be concluded that both the types of divisions are important in a living organism. Mitosis helps in growth and repair of the body cells by adding new cells while meiosis helps in maintaining the ploidy level of an organism.