I. MITOSIS A. Cell Division: 1. Needed for normal growth, repair, & development 2. Occurs in somatic cells (body cells) 3. Daughter cells have an exact copy of DNA of parent cell 4. Two daughter cells

B. Why Do Cells Divide? 1. Volume Limit: a) food intake b) waste removal 2. Volume to Surface Area Ratio

II. Cell Cycle

A. Interphase 1. Not part of Mitosis 2. 90 % time here 3. Carries out metabolic processes: Making new molecules & organelles Normal growth/development Cell prepare for division 4. DNA replication 5. Chromosomes are not distinguishable (chromatin) 6. Prepares for cell division

7. Cell Cycle: 1. G1 phase (normal growth) 2. S phase (synthesis 3. G2: prepares to divide 4. Mitosis/Cytokineses

Mitosis Begins Cell Cycle Continues

B. Prophase 1. First stage of mitosis 2. Chromosomes appear (shorten & thicken = sister chromatids) 3. Centrioles, spindle fibers appear 4. Nuclear membrane dissolves

C. Metaphase 1. Chromosomes line up at the equator

D. Anaphase 1. Chromosomes separate and migrate to the opposite ends of the cell

E. Telophase 1. Reorganization a) spindle fibers disappear b) nuclear membrane forms 2. Chromosomes lengthen & disappear 3. Cytoplasm splits (cytokinesis) into two daughter cells Cell Plate forms for plant cells

Mitosis in Animal Cells

Mitosis in Whitefish Blastula

Cytokinesis in Plant Cells

Mitosis in Plant Cells

Mitosis in Onion Root Tip

F. Significance 1. TWO Daughter cells 2. Identical DNA to parent cell 3. Healing Growth http://hybridmedicalanimation.com/anim_mitosis.html http://images.google.com/imgres?imgurl=http://iknow.net/images/screen_sisterchroms_512.jpg&imgrefurl=http://iknow.net/CDROMs/cell_cdrom/cell_dvd.html&h=384&w=512&sz=33&hl=en&start=5&tbnid=JWsP3BF4AY07QM:&tbnh=98&tbnw=131&prev=/images%3Fq%3Dmitosis%2Bvideo%26gbv%3D2%26hl%3Den%26sa%3DG

G. Cell Cycle From Individual Daughter cell  complete cell division Two Parts: a. Interphase: G1, S, G2 b. Mitosis/Cytokinesis

H. Role of the Cell Cycle A. Nearing the end of G1, two options: 1. Continue cell cycle; committed to initiating DNA OR 2. GO (resting phase): cell remains viable and metabolically active but are nonproliferative (don’t reproduce) 3. Cancer cells avoid entering GO or go through very quickly

http://images. google. com/imgres. imgurl=http://iknow http://images.google.com/imgres?imgurl=http://iknow.net/images/screen_sisterchroms_512.jpg&imgrefurl=http://iknow.net/CDROMs/cell_cdrom/cell_dvd.html&h=384&w=512&sz=33&hl=en&start=5&tbnid=JWsP3BF4AY07QM:&tbnh=98&tbnw=131&prev=/images%3Fq%3Dmitosis%2Bvideo%26gbv%3D2%26hl%3Den%26sa%3DG Cell cycle

B. Tumors and Cancer 1. Tumor: mass of cells formed from out of control cell reproduction 2. Benign tumors: abnormal mass of normal cells -remain at original site 3. Malignant tumor: abnormal rapidly dividing cells 4. Metastasis: spread of cancer cells http://www.youtube.com/watch?v=bDjDw18HJto http://www.youtube.com/watch?v=rrMq8uA_6iA&NR=1 (metastasis)

C. Protein p53 (Tumor Suppressor Gene) 1. Protein to control cells w/damaged DNA: a. code to stop cell cycle b. repair DNA c. program cell death 2. Mutation of p53 gene a. found in many cancers b. does not stop mitosis http://www.learner.org/channel/courses/biology/archive/animations/hires/a_cancer3_h.html