Why do Cells Divide? .... Growth, reproduction, repair.
G1 Checkpoint - Check to
see if DNA is damaged
G2 Checkpoint - Check to see if DNA is replicated properly
M Checkpoint - spindle assembly checkpoint, check for alignment of chromosomes
Apoptosis - programmed cell death, if any of the checks fail
G1 (Gap1) = growth and new organelles
S = synthesis of DNA
G2 = preparation for cell division
Mitosis = nuclear division
Interphase - cell growth, preparation for division, DNA synthesis.
Mitosis - The division of the nucleus that results in identical complete copies of chromosmes packaged into two new nuclei.
Occurs in 4 phases: Prophase, Metaphase, Anaphase, Telophase
Cytokinesis - The division of the cytoplasm that results in two daughter cells. Plants build a new cell wall. Animal cells pinch inward.
Mitosis produces 2 daughter cells that contain the exact same number of chromosomes as the original parent cell. Daughter cells are DIPLOID
Spindle = fibers attached to the centrioles that pull chromatids apart during anaphase
Paclitaxel is a cancer treatment drug that targets the tubulin in the spindle, preventing its formation. Taxol, in effect, blocks mitosis.
neoplasm: abnormal growth of cells | benign: non-cancerous | malignant: cancerous
Cancer: cellular growth disorder that results from the mutation of genes that regulate the cell cycle
Oncology - the study of cancer
10. In humans, each cell (except sex cells) has how many chromosomes? ______
11. After mitosis, how many daughter cells are produced? _______
12. After mitosis (in a human cell), each daughter cell has how many chromosomes? _____
13. How many phases are in MITOSIS? ___________
14. Which phase of the cell cycle is the longest? _________
15. During which phase does cytokinesis begin? __________
16. What cell parts migrate to the poles during prophase? __________________
17. What structure holds the two chromatids together? ____________________
18. During which phase does the nuclear membrane dissolve? __________________
19. What structure moves the chromosomes into position and then pulls them apart? ___________________
20. What is the overall purpose of mitosis? _________________________