1. CELL CYCLE NOTES

2. 1. Growth and Development
Multicellular organisms begin life as a single, microscopic cell called a zygote (fertilized egg).
The zygote develops into an embryo and eventually into a complex multicellular organism.
* So how do they become complex, multi-cellular organisms……

3. Organisms grow by increasing their number of cells through the process of cell division.
Cell Division: stages of the cell cycle (mitosis & cytokinesis) where a cell divides and creates new cells.
Ex: 1248163264

4. As the embryo develops, its cells begin to differentiate (their cell structure changes).
Cells specialize to perform specific jobs or functions in the multicellular organism.
Ex: brain cells, heart cells, lung cells, kidney cells, etc.

5. Quick Write
1. Explain how we grow from one cell (the fertilized egg) to many cells becoming multicellular organisms having different cells with specific jobs or functions.

6. 2. Cell Cycle
Cell cycle has three stages: Interphase, Mitosis and Cytokinesis (last step of mitosis).

7. 1. Interphase: long period of growth & development.
Cell spends most of its time in this stage of the cell cycle.
DNA called chromosomes during mitosis.
Chromosomes: coiled up chains of DNA.

8. 2. Mitosis: equal division of the nucleus (chromosomes).
Sometimes called cell division.
Creates 2 identical cells called daughter cells (at end of mitosis + cytokinesis).

9. Daughter cells have same number of chromosomes as parent cell.
Ex: parent cell has 12 chromosomes, so both daughter cells each have 12 identical chromosomes.
Has 4 stages/phases: prophase, metaphase, anaphase and telophase.

10. 3. Cytokinesis: equal division of the cytoplasm.
Final stage of mitosis/cell cycle that results in 2 new identical daughter cells.
Mitosis + cytokinesis = cell division

11. Quick Write 2. a. What are the names of the three stages of Mitosis?
b. What happens in the last stage?

12. 2 identical cells with same # of chromosomes
B. Interphase + Cell Division (mitosis & cytokinesis) = Cell Cycle
1. illustration shows a parent cell dividing to make new daughter cells.
metaphase
anaphase
interphase
prophase
telophase
longest
stage
cytokinesis
**make sure to label the illustration on your notes
2 identical cells with same # of chromosomes

13. Cell Cycle Interphase Interphase
cell grows and carries out normal activities; organelles duplicate
DNA replicates
Interphase
cell grows and prepares for mitosis

14. Click on the link below and enter the web code to do an interactive activity on mitosis
web code: cep

15. Cell Cycle Notes Summary
Write 5 questions that will help you learn.
Write a summary about the cell cycle. In your summary you should include:
the purpose for the cell cycle
how from a zygote the cell cycle creates multicellular organisms
a sentence of information about each step of the cell cycle: interphase, mitosis & cytokinesis