Question

what role does meiosis play in making sure you have the necessary genes and what role does mitosis play in assuring each of your cells has the necessary instructions for doing their work? Please be specific

Answer 1

Meiosis is the process by which haploid cells or gametes are produced by reducing the number of chromosomes within a parent cell to half. In the process, the parent cell, say it is diploid (2n) {n= number of chromosomes}, that is the parent cell has two copies of each chromosome undergoes two rounds of cell divisions (termed as Meiosis 1 and Meiosis 2). In Meiosis I, first the parent cell synthesizes a duplicate copy of each of its chromosomes, so now the parent cell is tetraploid(4n), then it divides equally into two daughter cells, each having diploid(2n) number of chromosomes. These (2) daughter cells next undergoes another round of cell division ( Meiosis 2). giving rise to four (two each) new daughter cells, each having one copy(n) of each chromosome (sister chromatid). These are the haploid (n) gametes and they have one copy(n) of each chromosome of the parent, hence these gametes are representative of the genetic constitution of the parent. These haploid(n) gametes can fuse with similar haploid(n) gametes from the parent cells of opposite sex giving rise to a new diploid(2n) zygote having genetic characteristics of both the parents.

Mitosis is a process by which a parent cell {say, diploid(2n)} divides to produce daughter cells which are also diploid(2n). The process involves initial duplication of each chromosome in the parent cell, resulting in the parent cell to become tetraploid(4n), followed by a single cell division such that each of the two daughter cells receives two copies of each chromosome hence become diploid(2n). During the process, the organelles are also divided roughly equally among the daughter cells. Hence, the daughter cells are exactly same as the parent cell and possess all necessary components, chromosomes (2n) and organelles, required for their proper functioning.