1.6 Cell division

1. 1.6 Cell division

2. Mitosis is the division of the nucleus of eukaryotic cells into two genetically identical daughter nuclei. Mitosis occurs during embryonic development, growth, tissue repair and asexual reproduction. Four phases of mitosis: prophase, metaphase, anaphase and telophase.

3. Interphase, a very active phase of the cell cycle with many processes occurring in the nucleus and cytoplasm, is the period before mitosis begins. During interphase: DNA is replicated in the nucleus in the S phase, and protein synthesis occurs in the cytoplasm; each part of a duplicated chromosome is called a sister chromatid (joined at the centromere)

4. the number of mitochondria (and chloroplasts in plant and algae cells) increases plant cells synthesize cellulose and use vesicles to add it to their cell walls

5. Sequence of events during mitosisSee BCC pg. 53-54

6. Prophase

7. Metaphase

8. Anaphase

9. Telophase chromosomes reach the poles and are pulled together in a tight group near the centrosome nuclear membrane forms around each group chromosomes uncoil nucleolus forms division of cytoplasm begins

10. Cytokinesis occurs after mitosis and is different in animal and plant cells. In animal cells: plasma membrane is pulled inward by contractile proteins to form a cleavage furrow at the equator cell is pinched apart into 2 genetically identical daughter cells

12. In plant cells: vesicles move to the equator and fuse to form tubular structures across the equator eventually the tubular structures merge to form 2 layers of membrane across the equator, which develops into the plasma membranes of the daughter cells pectins, cellulose and other substances are brought by vesicles to the equator and are deposited by exocytosis to form new cell walls for each daughter cell