mitosis notes (cell cycle) for blog
TRANSCRIPT
- 1.Biology Cell Reproduction Notes
2.
- New cells are created in your body every day.Think of three reasons why your body might need new cells.
3.
- Unicellular organisms - asexual reproduction
- Multicellular organisms- growth & repair.
4. 5. Cell Cycle
- Interphase- the longest part of the cell cycle: growth, metabolism & preparation for division occurs. Chromosomes are replicated. (S phase)
- Mitosis -the division of the nucleus.
- Cytokinesis-the division of the cytoplasm.
6. The Steps of Mitosis
- PMAT (remember the order that they occur)
- Mitosis produces two cells with the same number of chromosomes.
7. Prophase (Preparing)
- Longest phase of mitosis
- Nuclear envelope & nucleous disappears.
- Chromosomes become visible.
- Centrioles (animal cell) form and move to opposite poles of cell
- Spindle fibers form from centrioles, cross cell and attach to the chromosomes.
8. Metaphase (middle)
- Chromosomes line up in themiddleof the cell.
- Spindles are attached to them.
9. Anaphase (Apart)
- Spindle fibers begin to shorten.
- This pulls chromosomes apart.
- Chromosome halves are now referred to as chromatids.
10. Telophase (Two cells)
- Chromatids reach poles.
- Chromosomes become chromatin.
- Spindle fibers break down.
- Nucleolus and nuclear envelope appear.
11. Cytokinesis(happens during telophase)
- Division of cytoplasm
- In animal cells: cell membrane continues to pinch in until two cells are formed
- In plant cells: cell plate forms in center of cell and eventually splits cells
- At the end of mitosis, two new daughter cells are produced.