Cell Cycle (Main Idea) Cells grow until they reach their size limit, then they either stop growing or divide. The cell cycle is a set of stages. Body cells are also called somatic cells and they reproduce with mitosis.

All eukaryotic cells store genetic information in chromosomes Human body cells have 46 chromosomes or 23 identical pairs

Write this on the back at the bottom of your notes. Chromosomes: Each chromosome is composed of a single, tightly coiled DNA molecule. Chromosomes can’t be seen when cells aren’t dividing and are called chromatin.

Duplicated chromosomes are called chromatids & are held together by the centromere.

Phases of the Cell Cycle Interphase Mitosis prophase metaphase anaphase telophase Cytokinesis

Phases of the Cell Cycle Interphase (has 3 parts): Cell spends the most of its life in interphase! G1- primary growth phase (cells increase in size) S – synthesis; DNA replicated G2 – the cell continues to grow in size and prepare for mitosis. Mitosis (prophase, metaphase, anaphase, telophase) Cytokinesis

Mitosis Mitosis - Nuclear Division Prophase Metaphase Anaphase Telophase

Prophase Chromosomes become visible. Nuclear membrane breaks down. Centrioles and spindle fibers appear.

Metaphase Chromosomes line up in the middle of the cell. Spindle fibers attach to the centromere of the chromosomes.

Anaphase Duplicated chromosomes separate. Spindle fibers pull chromosomes away from each other. Cytoplasm division begins.

Telophase Two new identical daughter cells are formed. Chromosomes begin to uncoil and become less visible. Cytoplasm division occurring (Furrowing in animal cells; Formation of cell plate in plant cells).

Cytokinesis The cytoplasm divides resulting in 2 new identical daughter cells. Each new cell has identical nuclei. Different in plant and animal cells. Plant cells, cell plate reaches the cell wall. Animal cells, Furrowing completes and cell pinches off into two new cells.

Label your Cell Cycle Diagram

Name the 2 main phases of the cell cycle. 2. Name three things that can form during the cell cycle. 1. Interphase and Mitosis 2. Cell grows, DNA Replicates, Mitosis (nuclear division)

3. In what PHASE do most cells spend the majority of their lifetime. 4 3. In what PHASE do most cells spend the majority of their lifetime? 4. Name the 3 stages in interphase. 3. Interphase 4. G1, Synthesis (DNA Replication), G2

5. What does G1 stand for and what occurs in this stage. 6 5. What does G1 stand for and what occurs in this stage? 6. What does S stand for and what occurs in this stage? 7. What does G2 stand for and what occurs in this stage? 5. Cell growth – the cell grows 6. Synthesis – DNA Replicates 7. Growth, cell preparing for mitosis

8. What is another name for body cells? In which phase of the cell cycle does DNA replicate? During which phase are your chromosomes replicated? 8. Somatic Cells 9. Interphase 10. Interphase

11. Name the 4 stages of Mitosis in the diagram below. 3. ________ 1. Anaphase 2. Prophase 3. Telophase 4. Metaphase 1. _____ 2. ______ 4. _________

12. How many chromosomes are in a human body cell? 12. 46

13. A disruption in the cell cycle can lead to. 14 13. A disruption in the cell cycle can lead to? 14. Cancer cells rob the body of what? 15. If you were to slow down mitosis (nuclear division) and you had a cut on your skin. What would happen to your healing process? 13. Cancer 14. Nutrients 15. it would slow down because the cell is not dividing.

Station 9 16. During Meiosis, homologous chromosomes exchange genetic material. This exchange of genetic material ______________________. 17. Meiosis provides - 16. Increases the genetic variation. 17. chromosomal variation (genetic variation)

18. Are stem cells differentiated cells or undifferentiated cells? 19. Examples of differentiated cells are: 20. Can environmental conditions affect which genes will be expressed? 18. Undifferentiated cells 19. heart muscle, nerve cells, liver cells 20. yes

21. Which phase would a DNA mutation take place during the cell cycle 21. Which phase would a DNA mutation take place during the cell cycle. 22. Cells pass through a G2 checkpoint before entering mitosis. If DNA damage is detected the cells do NOT enter mitosis until the damage is repaired. Why is DNA damage repaired before cells enter mitosis? 21. S phase 22. So that healthy daughter cells are produced, allowing the organism to continue growing.

Station 11 Which of the following include all of the others? Interphase Cell Cycle Mitosis

Station 12 Which phase of Mitosis is taking place in the diagram below?

Station 13 Which phase of Mitosis is taking place in the diagram below?

Station 8 What is a karyotype? Chromosomes arranged in decreasing size. The first 22 are autosomes and the last set of chromosomes tell the gender.