Saturday, December 7, 2013

Compare and contrast mitosis and meoisis. How does the chromosome number of the daughter cell compare to the chromosome number of original cell?

Mitosis is cell division. The result of this process is
two identical daughter cells, each with the same number of chromosomes as the parent
cell. This process is used by unicellular organisms as a method of reproduction, and is
used by multicellular organisms for growth and for repair of old worn out cells. The
amount of chromosomes in the parent cell is called the diploid number which is
represented by 2n. Before mitosis begins, the amount of chromosomes in that cell
replicates. Therefore, each chromosome is copied. Then, the cell eventually divides into
two daughter cells, but each gets a full set of chromosomes, but, only half of the
cell's cytoplasm goes to each identical daughter cell. In meiosis, which is also a
reduction division, this occurs in the organism's gonads, namely ovaries or testes. The
end result is four haploid cells called gametes, which contain half the amount of
chromosomes the original cell contained or the (n) amount. In meiosis, the ovary or
teste cell contains the diploid or 2n amount of chromosomes. Just as in mitosis, these
are replicated. The cell then proceeds to divide into two cells, each with the diploid
amount of chromosomes. A second meiotic division occurs, resulting in four haploid
cells, with half the chromosome amount. In females, one of these cells becomes an ova or
egg, and the other three cells, or polar bodies, disintegrate. If it is a male, four
sperm cells are the result. Remember, that at fertilization, if a sperm(n) plus and
egg(n) unite to form a zygote, it will have 2(n) or diploid amount of chromosomes
again.

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