By A.K. Matai
Mitosis is the process by which a eukaryotic cell nucleus splits into two followed by the division of a parent cell into two daughter cells. During prophase, the replicated chromosome is condensed into a structure consisting of two sister chromatids held together by the centromere. Two DNA binding proteins – condensin and cohesin – help condense the chromosomes. Condensin condenses the chromosomes into a highly compact form while cohesin holds the sister chromatids together. In metaphase, chromosomes align along the metaphase plate. During anaphase, cohesin breaks down and the sister chromatids are pulled apart to opposite ends of the cell. Telophase and cytokinesis mark the end of mitosis as the nucleus is reformed and the cells is physically split into two daughter cells.
What is n? What is c?
n is the number of chromosomes present in a haploid cell while c is the amount of DNA present in a haploid cell. Here is a graph outlining the changes in n and c value throughout mitosis and meiosis.
The Moment of Truth
Now is the time to visually combine the concepts of mitosis, meiosis, n value and c value. Here is a diploid organism that has 2N=6 going through mitosis and meiosis with the n and c values clearly labeled.
Questions, Comments or Concerns?
Feel free to post a your questions, comments or concerns down below!
Locke, John; Deyholos, Michael; Harrington, Michael; Canham, Lindsay; Kang, Min, “Open Genetics Lectures (OGL) Fall 2016”
Evan Amos. M&Ms. 2011. https://commons.wikimedia.org/wiki/File:Plain-M%26Ms-Pile.jpg. Web. 19 Mar. 2017.