- Interphase - unable to see the process of DNA replication
- The first sign that the cell is entering mitosis and DNA division is when we see the break down of the nucleus, this phase is known as the "Prophase", the membranes brake down and the chromosomes become visible. They are visible as a pair of chromatids.
- Once the nucleus is gone, inside the cell, a network of protein molecules known as the "Spindle" and the "spindle fibres" that extend from one pole of the cell to the other. This is the "Late prophase" - The pair of chromatids will move towards the spindle and join onto one of the spindle fibres at the centrameere
- "Metaphase" - the pair of chromatids are attached to the spindle fibre by the centrameere. Characteristics = the chromosomes are in the middle, arranged across the equator of the cell
- The "Anaphase" - the spindle fibre shortens, pulling one chromatid in one direction and another in the other direction. The pair of chromatids are move apart and move to the poles of the cell. The pair of chromatids are separated.
- "Telophase" - The nucleus begins to reform around the chromosomes at either end of the cell. This will be the new nucleus of the new cell. See the formation of two nuclei, two sets of chromosomes at opposite ends of the cell
- "Cytokinesis" - The cells splits in two - NOT part of mitosis. The cell begins to move in-words in the middle, dividing the cytoplasm in half and the membrane will fuse across the equator to form the two cells. They each contain a chromosome. Both cells have chromosomes that are the same as the parental cell.
- In humans, we don't see one pair separating, but 23 pairs separating at the same time
ไม่มีความคิดเห็น:
แสดงความคิดเห็น