Cell Cycle (Phases)
Part 1: Cell Division
A. M Phase- Division of the nucleus.
B. Cytokinesis- Division of the cytoplasm.
Part 2: InterphaseA. G1 phase- Offspring cells reach maturity.
B. S phase- DNA and chromosomes are copied.
C. G2 phase- Cell waits to divide.
- Cells can exit the cycle at G1 and enter G0 phase.
- No chromosomes copied; no cellular division.
- They die at maturity.
The Mitosis (Phases)
A. Chromosome pairs become shorter and thicker. (paired in "S" phase of Interphase)
B. Nuclear membrane begins to disappear.
C. 2 dark chromosomes appear next to the nucleus.
D. Spindle Fibers extend from the centrosomes as they move towards opposite sides of the cell, creating an early Mitotic Spindle.
A. The Mitotic Spindle becomes easy to see.
B. Kinetochore Fibers move chromosomes towards the middle of the cell.
C. The nucleus disappears.
A. The chromatids of each chromosome separate and move towards the centrosomes.
B. Each chromatid is considered one new chromosome.
A. Chromosomes reach opposite ends of the cell.
B. Spindle Fibers disappear.
C. Nuclei reforms around each set of chromosomes.
2. Anaphase- Spindle fibers move homologous chromosomes to opposite sides
3. Telophase-Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed
4. Metaphase 2- Chromosomes line up along equator, not in homologous pairs
5. Prophase 2- Chromosomes line up along equator, not in homologous pairs
6. Anaphase 2- Chromatin separate
7. Metaphase- Homologs line up alone equator
8. Telophase-Cytoplasm divides, 2 daughter cells are formed