Cell Cycle Review

What is the correct sequence of the 5 stages of the cell cycle? G1  S  G2  M  C 2. Define the following terms: Chromatid- duplicate half of a chromosome Mitosis- division of the nucleus Cell differentiation- cells increase in # and become specialized in structure and function. Cytokinesis- division of the cytoplasm Centromere- a disk that attaches 2 chromatids to each other

f. cancer- doesn’t respond to normal signals that shut down cell division g. checkpoints- critical point where stop and go signals regulate the cell cycle h. diploid- 2n, chromosomes found in pairs, has 2 homologues of each chromosome i. haploid- half the # of chromosomes j. Crossing over- chromosomes exchange segments of DNA k. zygote- fertilized egg l. Asexual reproduction- involves 1 parent m. Sexual reproduction- joining together of 2 gametes

3. In the space provided, draw and identify the phases of mitosis 3. In the space provided, draw and identify the phases of mitosis. see FRAME 4. Describe the events that occur in each phase of mitosis. Prophase- nuclear membrane breaks down, spindle fibers form Metaphase- chromosomes align along the equator of the cell Anaphase- sister chromatids separate to opposite ends of the cell Telophase- nuclear membrane reforms, spindle fibers disappear, cytokinesis begins

5. A typical human cell contains 46 chromosomes 5. A typical human cell contains 46 chromosomes. After mitosis and cytokinesis, how many chromosomes would the daughter cells contain? 46 6. Describe the events that occur in the interphase of the cell cycle. G1- growth S-DNA replication G2- growth, maturing 7. In which phase of the cell cycle does the cell spend most of its life? Interphase

8. Distinguish between cytokinesis in plant cells and cytokinesis in animal cells. Plant cells- cell wall divides cytoplasm Animal cells- cleavage furrow divides cytoplasm 9. After which phase does cytokinesis begin? Telophase 10. Which phase is not a part of mitosis? Interphase 11. Mitosis ends when the daughter cell reaches which phase?

12. How many daughter cells are produced as a result of mitosis 12. How many daughter cells are produced as a result of mitosis? 2 and meiosis? 4 13. Name at least 2 factors that trigger cell division. Growth Enzymes from other cells 14. What is the difference between benign and malignant tumor? Benign tumor- stays at the original site Malignant- spreads and impairs the function of other organs

15. Give an example of a physical factor that would turn off cell division. When cells are densely packed together 16. If the body’s immune system does not destroy an abnormal cell, what will happen to that cell? It will become a cancer cell 17. What is an example of an internal signal? Enzymes/hormones (come from inside the cell) 18. How many chromosomes are in the body cells of an organism that has a haploid number of 8? 16

19. DNA becomes more compact by wrapping tightly aroudn associated proteins. Why does this occur? So they will fit within the cell 20. How many chromosomes exist in the human body? 46 chromosomes 21. What is the difference in Anaphase of mitosis, anaphase of meiosis I, and anaphase of meiosis II? Chromatids do not separate at the centromere in anaphase I, they do in mitosis and meiosis II

22. The diploid number of chromosomes in a human skin cell is 46 22. The diploid number of chromosomes in a human skin cell is 46. How many chromosomes are in a human sperm cell? 23 23. Describe cell differentiation. Cells not only increase in number, but become specialized in function 24. How many sex chromosomes are in the body? 2 How many pairs of chromosomes are in the body? 23 pairs How many autosomes are in the body? 44

25. Name a factor that triggers cell division 25. Name a factor that triggers cell division. Growth Test: 59 Questions *45 cell cycle (multiple choice) *5 biochemistry (multiple choice) *5 cells (multiple choice) *4 short answer

In addition… Be able to: Explain why mitosis needs to produce identical daughter cells Explain why reduction-division is important for sexual reproduction Compare and contrast the phases of mitosis, meiosis I and meiosis II Discuss cancer