This latter idea is what occurs in meiosis. Construct a simple model of DNA and model the process of replication. If all 4 chromosomes separated from each other and the cell was able to divide into quarters rather than halves, that would yield 4 1n cells. So, mitosis's main function is literally DNA replication. And meiosis generates reproductive cells with new combinations of gene variations. That means that it has the same DNA and number of chromosomes as the previous cell. Mitosis builds a person with an identical set of chromosomes in every cell. You are correct in that it is 2 sets of 2n rather than 4n, since the convention would indicate 4n as a tetraploid (many types of plants are in fact tetraploid, ).Īt the end of the mitotic cell cycle, cell division functions to separate the 2 sets of 2n chromosomes into two distinct cells, each containing 2n chromosomes. Explanation: In mitosis, the cell splits apart to form two identical, same cells. During S phase the cell duplicates its DNA content generating 2 sets of 2n chromosomes (2 copies of 46 chromosomes for a total of 92 chromosomes in the human case). Prior to S phase, diploid cells contain 2n content (maybe "content" refers to "C" notation?) of DNA. This ensures that each daughter cell gets a copy of the genome, and therefore, successful inheritance. During meiosis, the genome is replicated as in mitotic cells, but subsequently one round of DNA replication is followed by two rounds of chromosome segregation. We have 23 unique chromosomes (22 regular chromosomes and 1 sex chromosome), but we have 2 variants of each chromosome to give us a total of 2*23 = 46 chromosomes. Cells must replicate their DNA before they can divide. The multiplying number - "2" in the diploid case - refers to the number of versions of each unique chromosome. Eukaryotic cells are generally diploid, or 2n. The "n" refers to the number of unique chromosomes within a cell.
While I've not heard of the "C" notation previously, "n" is common notation that indicates the ploidy of a cell.
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