Biology...MITOSIS and MEIOSIS??

Question

Why do all somatic cells undergo mitosis, while only certain cells in the gonads undergo meiosis?

Thanks so much!

Answer 1

Mitosis is the reproduction of somatic, or body cells. These cells are only used for the body, and not for reproduction with gametes. somatic cells have a diploid chromosome number, described as 2n, which means they have two copes of every chromosome. Gametes undergo meiosis, which is a process in which four gametes are made, and are all haploid in number. Haploid cells only carry half the normal chromosome number, and can be described as 1n. With this, after sexual reproduction the gametes from two individuals can fuse to for a zygote. Since each gamete is only half the chromosome count, they both together create a diploid cell. The diploid cell of a zygote then forms the somatic cells, it is basically a cycle.  The gametes in meiosis allow us to reproduce and produce a regular chromosome cound of 46. Mitosis is also one round of cell division, while meiosis is two.

Answer 2

When cells undergo mitosis, all of the chromosomes are duplicated to create an entire new cell.  But when cells undergo meiosis, only half of the chromosomes are copied.  s*x cells only need half of the normal amount of chromosomes because they ultimately combine with another s*x cell to create an embryo.  Together, the egg and the sperm have the total amount of chromosomes in a normal cell.