For our nematodes example, each cell after MITOSIS should contain four chromosomes given that its diploid number in four. In humans, the case is that the each of the 46 chromosomes will be present in the daughter cells after mitosis. The whole point of mitosis is to make exact copies of the parent’s cells, so that each cell produced has the same genetic information as its parent cell. ![]() The misconception in many of the comments below is that the article, and its diagrams, are depicting meiosis, when they are actually describing MITOSIS. But hopefully the rest helps clear up some things as well. The most important thing to remember that will clear up the confusion, I think, is that after DNA is replicated in S phase, the 2 sister chromatids (or 2 copies of each chromosome) are still linked together and still considered to be just 1 chromosome. This could look like: A, b, C, D, e, f, g, H, i, j, K, L, M, n, o, p, q, R, s, T, U, v, w, X Germ cell (after meiosis II): 23 chromosomes, 23 chromatids, 0 pairs of homologous chromosomes, 0 pairs of sister chromatids. In a male this would look like: AA aa, BB bb, CC cc, DD dd, EE ee, FF ff, GG gg, HH hh, II ii, JJ jj, KK kk, LL ll, MM mm, NN nn, OO oo, PP pp, QQ qq, RR rr, SS ss, TT tt, UU uu, VV vv, WW ww, XX YY Somatic cell (after S phase, before mitosis/meiosis): 46 chromosomes, 92 chromatids, 23 pairs of homologous chromosomes, 46 pairs of sister chromatids Somatic cell (before S phase): 46 chromosomes, 46 chromatids, 23 pairs of homologous chromosomes, 0 pairs of sister chromatidsįor a male, this would look like: A a, B b, C c, D d, E e, F f, G g, H h, I i, J j, K k, L l, M m, N n, O o, P p, Q q, R r, S s, T t, U u, V v, W w, X Y Or, you could say you have 46 pairs of sister chromatids, but still 23 pairs of homologous chromosomes. In this way, you do have 92 chromatids, but still only 46 chromosomes. However, the 2 'A' chromatids are still linked together by the hip, and thus are considered to still be only one chromosome. When DNA is replicated, you now have 2 copies of the 'A' chromosome (or 2 'A' chromatids) and 2 copies of the 'a' chromosome (2 'a' chromatids), 2 'B' and 2 'b', and so on. 'A' and 'a' are still 2 different chromosomes, though they are homologous to each other (code for the same genes). ![]() you have an 'A' chromosome (1 'A' chromatid) and an 'a' chromosome (1 'a' chromatid), 'B' and 'b', 'C' and 'c' and so on, each coming from a different parent. ![]() In a regular somatic cell (before DNA is replicated in the S phase), there are 46 chromosomes - 23 of each kind as well as their homologous opposite. Both mitosis and meiosis occur in multiple stages including DNA replication and condensation, nuclear membrane degradation, spindle formation, chromosomal segregation, and nuclear reformation.I think another way to think about it is remembering the difference between "sister chromatids" and "homologous chromosomes". The first round of division is different from the second, the second round is much similar to mitosis. Note: In meiosis, prophase, metaphase, anaphase, and telophase occur twice. Recombination and crossing over take place between homologous chromosomes. Mother cell can either be haploid or diploid This type of cell division occurs in meiocytes (specialized cells)ĭifferent stages are – Prophase, metaphase, anaphase, and telophaseĭifferent stages of meiosis are – Prophase I, metaphase I, anaphase I, and telophase I and then enters into Meiosis II which includes the following phases Prophase II and then metaphase II, anaphase II, and telophase II. This type of cell division occurs in all types of cells, even sex cells
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