Mitosis Faris Al-Ahmadi
18th October, 2010
Table with 100 cells recorded in an onion root tip to show which stage of mitosis each cell is in
Table with 100 cells recorded in a different onion root tip region to show which stage of mitosis each cell is in
*These uncertainties are an estimated non-systematic (human) error during the practical.
= ± 5 Cell Error Margin
- Describe the events occurring in each stage of mitosis emphasizing the movement of chromosomes.
Prophase: This phase is the first phase in mitosis. In prophase, chromatids formed from interphase are starting to be shown as chromosomes, since they are shortening and thickening, making them more visible to a microscope. Each chromosome contains two sister chromatids, joined together by a centromere. The nuclear membrane of the nucleus starts to disappear, and so does the nucleolus. Centrioles in the cell start to move to either end of the cell, and they stay put at the ends. The centrioles start to produce mitotic spindles, which are extending across the cell.
Metaphase: The nuclear membrane is fully disappeared, and the mitotic spindles are rapidly extending across the cell. The spindles are then attached to the kinetochore of each chromosome, and the spindles align the chromosomes in the middle of the cell. They are aligned in the middle so that when separated in anaphase, the nucleus from the two daughter cells will get a copy from each chromosome.