mitosis meiosis

Mitosis evolved in complex plants and animals for growth and repair. Mitosis, the

division of a cell resulting in two identical daughter cells, prolongs an organism's life by

replacing old, dead, and damaged cells. In complex animals and plants, mitosis occurs

Meiosis evolved in complex plants and animals to increase variation in offspring

and to maintain the number of chromosomes from generation to generation. Meiosis

occurs in the sex cells of organisms, specifically the ovaries and testes in animals, and in

In an organism where n=8, the process of mitosis would be the following: In

interphase, the DNA would replicate, resulting in 16 chromosomes. In prophase, two

centrioles would move to the poles, the spindle starts to form, the nucleolus and nuclear

membrane disappear, and the kinetochore fibers attach to the chinetochores. During

metaphase, the chromosomes line up at the equator. In anaphase, the centromere splits,

and the chromosomes move to the opposite poles (8 to each pole), pulled by the

kinetochore fibers on the spindle. Lastly, during telophase, the spindle disappears, the

nucleolus and nuclear membrane reappear, and the cell separates resulting in two new

cells, exactly like the parent cell, each with 8 chromosomes.

Meiosis in an organism where n=8 would be the following: During interphase I,

the 16 chromosomes (2n=16) replicate to 32 chromosomes. In prophase I, centrioles

would move to the poles, the spindle starts to form, the nucleolus and nuclear membrane

disappear, and the kinetochore fibers attach to the chinetochores. Most importantly, the

pairing of homologous chromosomes and crossing over takes place. This step is very

important in creating variation among offspring. Next, the homologous pairs line up at

the equator in metaphase I. In anaphase I, the homologues, each cons

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