Biology / Unit 4: Cell Growth and Division
4.2 Mitosis
Notes
Mitosis divides the nucleus so each new cell gets an identical set of chromosomes. Remember PMAT.
- Prophase: chromosomes condense and become visible; the nuclear envelope breaks down; spindle fibers form.
- Metaphase: chromosomes line up in the middle of the cell.
- Anaphase: sister chromatids are pulled apart to opposite ends.
- Telophase: nuclear envelopes re-form around two sets of chromosomes.
- Cytokinesis: animal cells pinch in (cleavage furrow); plant cells build a cell plate.
- Result: 2 identical diploid daughter cells.
Practice
In which phase do chromosomes line up along the middle of the cell?
M for middle in metaphase.
A skin cell with 46 chromosomes divides by mitosis. How many chromosomes does each daughter cell have?
Mitosis makes cells identical to the parent cell.
How does cytokinesis differ in plant cells?
The rigid cell wall prevents pinching, so a new wall forms in the middle.
Ready for more? Take the Unit 4 test.