Cell Reproduction and Growth Cell Division M C

(phases in the life cycle of a cell) The Cell Cycle (phases in the life cycle of a cell) Interphase (G1, S, G2) Cell Division- Prophase Metaphase Anaphase Telophase Cytokinesis

What happens in each of these phases of the cell cycle?

Interphase Cell grows in size and metabolizes Chromosomes duplicated

G1-growth phase 1 S-synthesis G2-growth phase 2

1. Prophase Chromatin coils up into chromosomes Nucleus disappears (Chromosomes are made up of 2 sister chromatids attached by a centromere) Nucleus disappears Centrioles move to poles Spindle forms

2. Metaphase Chromosomes attach to the spindle and line up on the equator of the cell. Spindle fibers attach to each sister chromatid at the centromere.

3. Anaphase Sister chromatids separate and move to opposite poles as spindle fibers shorten

4. Telophase Chromatids reach poles Chromosomes unwind Nuclei reform Spindle fibers break down

5. Cytokinesis Division of the cytoplasm…separation of the 2 new cells

Cytokinesis: Animal vs. Plant Plasma membrane pinches in (cleavage furrow) Cell is pinched in two Cell plate laid down along equator Plasma membrane forms around each cell New cell walls form on each side of cell plate

Summary Mitosis

Check your BRAIN! Describe how a cell’s surface area-to-volume ratio limits its size. 2. Why is it necessary for a cell’s chromosomes to be distributed to its daughter cells in such a precise manner? 3. How is the division of cytoplasm different in plants and in animals? 4. List the 4 phases of mitosis.

Key Terms Chromosomes Chromatin Sister chromatids Centromere Spindle (spindle fibers) Centrioles Cleavage furrow Cell plate Interphase Prophase Metaphase Anaphase Telophase Cytokinesis