1. CELL CYCLE & MITOSIS

3. Today

5. Cell Cycle
90% of the cell cycle is in interphase, other 10% is mitosis (cellular division)
Interphase composed of 3 phases: G1, S, and G2
G1 (Gap 1) phase: cellular growth and protein synthesis, in preparation for the S phase
S (Synthesis) phase: DNA synthesis/replication of each chromosome in the cell, forms sister chromatids.
G2 (Gap 2) phase: cellular growth as well as protein & lipid synthesis, in preparation for mitosis
Ex. Synthesis of proteins used to form mitotic spindle

7. Mitosis Cellular division of a cell Makes exact copy of mother cell
Produces 2 identical daughter cells
Each product has same # of chromosomes
Purpose of mitosis?
To form a multicellular organism from a zygote
To replace dead or lost cells, such as skin and red blood cells

8. Phases of Mitosis: (PMAT) + cytokinesis
Prophase: chromosomes become visible, begin to condense
Prometaphase: nuclear envelope disappears and chromosomes attach to mitotic spindle
Metaphase: chromosomes line up at metaphase plate/equatorial plane
Anaphase: sister chromatids separate by kinetochores
Telophase: two daughter nuclei reform at the 2 poles
Cytokinesis (division of the cytoplasm) occurs simultaneously

10. Interphase
Prophase
Metaphase
Anaphase

11. Mitosis in plant cells differ from mitosis in animal cells
Plant cells do not form centrioles during mitosis
Plant cell walls are too rigid to form cleavage furrow
Forms cell plate instead

12. Telophase/cytokinesis in a plant cell
cell plate

13. Telophase/cytokinesis in an animal cell
cleavage furrow

15. Some terms
Gene: portion of DNA that encodes RNA and protein; determines your characteristics—freckles, height, eye color…
Chromosomes: contain DNA and protein; compact way of carrying all genetic info
Sister chromatids: copies of chromosomes joined together

17. Extra Credit Activity Mitosis through edible modeling
-All stages of mitosis need to be represented
(PMAT+cytokinesis)
-Each stage should have a notecard identifying the stage and labeling what is happening.
After presentation to the class (and possible photograph) of project, it may be disposed of as you see fit.