Hi guys, can anyone please post a chromosome/chromatin count at eac stage of Mitosis and Meiosis. Would greatly appreciate it! I'm confused even after using lots of sources. Thank you!
Mitosis/Meiosis chromosome count
- Thread starter flossit
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The key to understanding Cell division is to simplify the process, not complicate it. On the web, there are many different ways of looking at this concept, which is what may add to the confusion.
Mitosis, involves the division of the Somatic cell, which are diploid. This means that it consists of 2 sister chromatids, each has identical sequence of DNA. During Mitosis, sister chromatids separate into individual sister chromatids. At this point, they are considered individual chromosomes. Shortly after, cytokinesis (cell division) occurs and both mother and daughter cells have the same number of chromosomes.
For example, Before the onset of mitosis, a diploid cell, has 6 chromosomes, that means 12 sister chromatids. After cytokinesis (comes after mitosis) each cell has 6 sister chromatids. They will be duplicated soon in order to undergo another mitotic division.
Meiosis is a form of cell division that is only undergone by haploid cells ( cells in Ovaries and Testes). Meiosis reduces a diploid number of chromosomes to haploid number. Lets say before Meiosis there are 3 chromosomes (6 sister chromatids). The cell that has undergone Meiosis will now have only 3 sister chromatids, and is now called a gamete. It will only become diploid (acquire other 3 chromatids) if it undergoes fertilization = formation of a zygote. Zygote will become diploid with 6 sister chromatids or also called 3 pairs of chromosomes.
In human cells, Somatic cells have 23 pairs of chromosomes before mitosis and 23 chromosomes after cytokinesis. While after meiosis, each gamete will only have 23 chromosomes (not pairs). It will have 23 pairs only after fertilization.
Hope this helps.
Would that be right?
Mitosis: Diploid cell: 6 chromosomes (12 chromatids) - end 3 chromosomes (6 chromatids). (But i thought that chromosome would double, no?)
Meiosis: Haploid cell: start of “M1” with 6 chromosomes (12 sister chromatids) - end of “M1” with 6 chromosomes each has 2 chromatids. start of “M2" with 6 chromosomes - split into half chromatids and - end of “M2” is with 3 chromosomes.
Mitosis: Diploid cell: 6 chromosomes (12 chromatids) - end 3 chromosomes (6 chromatids). (But i thought that chromosome would double, no?)
Meiosis: Haploid cell: start of “M1” with 6 chromosomes (12 sister chromatids) - end of “M1” with 6 chromosomes each has 2 chromatids. start of “M2" with 6 chromosomes - split into half chromatids and - end of “M2” is with 3 chromosomes.
Would that be right?
Mitosis: Diploid cell: 6 chromosomes (12 chromatids) - end 3 chromosomes (6 chromatids). (But i thought that chromosome would double, no?)
Meiosis: Haploid cell: start of “M1” with 6 chromosomes (12 sister chromatids) - end of “M1” with 6 chromosomes each has 2 chromatids. start of “M2" with 6 chromosomes - split into half chromatids and - end of “M2” is with 3 chromosomes.
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dentalstudent2021
Mitosis - goes from same # of chromosomes in parent to same # in each daughter cell. ex: if parent had 8 chromosomes. each daughter cell will have 8 chromosomes (BUT these chromosomes used to be sister chromatids before). in short, they go from 2n to 2n. no reduction in number of chromosomes
Meiosis 1 - we have reduction of # of chromosomes. ex: we start with 4 chromosomes. each daughter cell will now have only 2 chromosomes, which is haploid!.
Meiosis 2 - now each cell from meiosis 1 continues here and has only 2 chromosomes in each. they will now go further reduction. the daughter cells here will have only 1 chromosome in each cell.
hope it helps.
Meiosis 1 - we have reduction of # of chromosomes. ex: we start with 4 chromosomes. each daughter cell will now have only 2 chromosomes, which is haploid!.
Meiosis 2 - now each cell from meiosis 1 continues here and has only 2 chromosomes in each. they will now go further reduction. the daughter cells here will have only 1 chromosome in each cell.
hope it helps.
