Mitosis

Mitosis is the process where one set of chromosomes is equally divide into two identical groups. Before this can happen, the chromosomes must be set up so that the separation can happen in an orderly way.

Both the alignment and separation processes happen because of the chromosomes interacting with microtubules. The microtubules become organized into a spindle, which forms early in mitosis, and then disassembles as mitosis is almost over. The centromere is were the two chromosomes are connected.

1.<Interphase> This phase of cell division is the longest. In this phase proteins are made and DNA is replicated as the cell continues to grow.

2.<Prophase> During this phase the nuclear membrane begins to disintegrate and the chromosomes become more apparent.

3.<Metaphase> This is the shortest phase and it will only last a few minutes. In this phase the chromosomes line up in the middle of the cell. Microtubules connect at the centromere of
each chromosome to the spindles at each pole of the cell.

4.<Anaphase> In this phase the chromosomes are split in half by the spindles where they are made into separate chromosomes at the opposite poles.

5.<Telophase> In this final stage of mitosis separate nuclei are formed and nuclear membrane begins to form.


Meiosis

Meiosis is the process by which cells divide into gametes. Gametes only have half the genetic material of the parent cell. In an organism, the gamete will only have one copy of each chromosome. The process of Meiosis I is very similar to mitosis. However, there is a major difference: In mitosis, the sister chromatids separate from each other in the first
division. In meiosis, the sister chromatids remain together and it is the homologues which separate in the first division.

1.<Prophase 2>During this phase the centrioles start to move toward the poles of the cell.

2.<Metaphase 2>This phase is similar to Metaphase in that the chromosomes line up at
a metacentric plate by spindle fibers.

3.<Anaphase 2>This phase is also similar to Anaphase in that the chromosomes divide into individual chromatids. Each sister chromatid will then end up on one side of the cell.

4.<Telophase II>At the end of this phase the nuclear envelopes form around each set of DNA and the cytoplasm divides once again. As a result, four haploid cells have formed from
one diploid cell. DNA and the cytoplasm divides once again. As a result, four haploid cells have formed from one diploid cell.