Question

“Mitosis and Meiosis I are very different, but Mitosis and Meiosis II are very similar. Therefore, Meiosis I must cause all the key differences between gametes and normal body cells.”
Do you agree or disagree with this statement? Support your claim with evidence and reasoning about cell division, body cells, and gametes.

Answer 1

Yes, I agree with statement b/c in meiosis I, specifically in prophase I the homologous chromosomes line and form tetrads in which they exhibit the act of ‘crossing over’ which allows for genetic diversity; This would not occur in mitosis as body cells are produced to repair or for growth so the division of cells must allow for the exact replication of DNA or it is not possible to repair the body or growth if there is genetic variation in each cell. Also, in Meiosis I, specifically when metaphase I occurs, it is impossible to predict how the homologous chromosomes will be split, therefore creating even more diversity of genes known as Independent assortment. None of these processes occur in meiosis II, as the exchange of DNA and act of genetic diversity has already occurred in Meiosis I, therefore Meiosis II simply has to go throwing regular cell division making it more similar to mitosis than Meiosis I; Independent assortment and crossing over are the processes that set Meiosis I to differ from the others.
(Go into more depth about how body cells have to be completely identical whereas gametes have to have genetic diversity)