1. BIOLOGY
Unit 4 Notes:
Mitosis

2. (1) What is Mitosis?
• Cell division for non-sex cells.
• Non-Sex Cells:
– Are also called Somatic Cells.
– Examples Skin, Hair, Muscle, Bone, etc.

3. (2) What happens during Mitosis?
• Cells make exact copies of themselves.
• Start with 1 cell, and end up with 2 identical
copies.
• Start “2n” or “Diploid”  End “2n” or “Diploid”
• 2n = Diploid = Full set of genetic information
– In Humans this means a full set of 46 chromosomes (or
23 pairs).

4. (3) Mitosis Phases
1.
2.
3.
4.
5.
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

5. (4) Prophase
• Nuclear membrane dissolves.
• DNA condenses into chromatin and then
chromosomes.
• Centrioles and Spindle Fibers inside the cell
prepares to move genetic material.
• Terms:
– DNA = Basic genetic molecule
– Chromatin = Wound up DNA
– Chromosomes = Wound up Chromatin

6. (5) Metaphase
• Pairs of sister chromatids line up at the metaphase
plate.
• Terms:
– Sister Chromatids: Identical copies of DNA or chunks of
chromosomes.
– Metaphase Plate: The very center of the cell.

7. (6) Anaphase
• Pairs of sister chromatids separate to opposite
ends of the

8. (7) Telophase
• The sister chromatids are fully separated.
• The nucleus starts to reform around genetic
material.
• The chromosomes unwind fully.

9. (8) Cytokinesis
• The cytoplasm splits.
• The cell membrane splits and reforms around the 2
new cells.
• Terms:
– Cytoplasm: The matrix filling the inside of cells.