Mitosis versus Meiosis

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Mitosis versus Meiosis Use this powerpoint with the chart that compares the events that happen in each phase of Mitosis and Meiosis

Mitosis: ■

If a cell wants to make a duplicate of itself, it first must copy its DNA (part of a chromosome).

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The copies then must be separated & sorted into two sides of the cell.

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The cell then splits in two. Part of each parent is carried to the two new cells.

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Results in 2 identical somatic cells such as internal organs, skin, bones, blood, etc.

Meiosis: ■

As in mitosis, if a cell wants to make a duplicate of itself, it first must copy its DNA (part of a chromosome).

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Results in reproductive cells (sperm, eggs, etc - called gametes). Part of each parent is carried to the four new cells, that carry a different gene combination

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Meiosis has evolved to solve a problem. The problem is this: organisms combine their genes together creating genetic diversity and trait diversity. Trait diversity increase the chances of survival of the species in the case of a change in the environment.

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In Mitosis, the nucleus divides one time In Meiosis, the nucleus divides two times

Interphase occurs just before Mitosis and Meiosis begin: DNA is replicated along with organelles and other cellular components and the cell prepares for division.

http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.ht m

Interphase is the same for

Mitosis and Meiosis The chromosomes have not yet condensed.

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

End of Interphase – chromosomes start to condense and replicate

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Meiosis has two steps: I and II

Meiosis I the first division of the nucleus

Meiosis I - Prophase I ( very similar to Prophase in Mitosis – difference is the formation of the tetrads)

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Tetrads are formed when the duplicated homologous chromosomes form pairs during Prophase I

Meiosis IMetaphase I

MITOSIS – METAPHASE

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Meiosis Anaphase I

Mitosis: Anaphase

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Meiosis Telophase I

Mitosis: Telophase

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Cytokinesis ■

Meiosis – two cells separate but nuclear membrane will not form

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Mitosis – two cells separate and nuclear membrane will form

Meiosis II is the second division of the nucleus

Meiosis II is very similar to Mitosis Meiosis II - Prophase II

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Meiosis Metaphase II ( same in Mitosis)

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Meiosis Anaphase II (same in Mitosis

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Telophase II (same in Mitosis ) follow Cytokinesis Final result: 4 new haploid cells called gametes

http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html