Name ______Date ______

Period # ______

CELL CYCLE AND MITOSIS

Use your textbook pgs 244-246 to explain (using at least 5 complete sentences) 3 reasons why cells must divide.

(1) Goto www.cellsalive.com (2) click on the cell cycle and watch the interactive and read about each step (3) draw the cell cycle in the space below (4) label interphase and mitosis (5) label and summarize in your own words what happens during G1, G0, S(synthesis), G2 and M (mitosis) (6) label and summarize in your own words what happens at each checkpoint.

(1) Goto www.cellsalive.com (2) click on mitosis, watch the interactive and read about each step (3) complete a drawing for each stage in the space provided in the following table. Make sure to show chromosomes, sister chromatids and centromeres where appropriate.

PHASES OF MITOSIS

STAGE / IMPORTANT EVENTS / DRAWING
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE

CELL DIVISION

CYTOKINESIS

NOW: use the statements below and write them in the above table (under “Important events” in whatever stage you think they belong.

·  Spindle fibers shorten, and sister chromatids are separated at the centromeres Sister chromatids travel to opposite poles of the cell.

·  Nucleus reappears

·  Each chromosome has 2 chromatids, both with the same genetic info

·  Centrioles are at opposite sides of the cell

·  Centrioles with spindle fibers start to go to opposite poles of the cell

·  New chromosomes unwind into chromatin

·  Nuclear membrane breaks down

·  Chromosomes attached to spindle fibers align at the center of the cell

·  Spindle fibers attach to centromere

·  Daughter chromosomes arrive at the poles and spindle fibers disappear

·  Chromatin condenses into chromosomes

·  Cytoplasm divides and cells pinch off. Each cell has its own new membrane

Meiosis. . . the same or different than Mitosis?

(1) Go to www.cellsalive.com (2) click on meiosis, watch the animation and (3) compare mitosis to meiosis by creating a Venn Diagram below (4) the following information must be included: phases of mitosis and meiosis; number of chromosomes at the start and at the end of both mitosis and meiosis; number of stages are in both mitosis and meiosis?; define crossing over, gametes, sex cells.

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