Pö ÿalima 02-26-10

Cell Division

You will need your computer today

10.2 Goals

I will be able to explain what happens in the cell cycle.

I will be able to explain and identify the stages of mitosis.

Mitosis10.2

Cell cycle = Life span of the cell

G1 phase – cell grows, makes more organelles and proteins

S phase – chromosome replication (S = synthesis = “to make”)

S phase

G1 phase

G2 phase

Chromosomes and Chromatid

Each chromosome made of two identical chromatids.

Attached together by the centromere

Cell cycle = Life span of the cell

G1 phase – cell grows, makes more organelles and proteins

S phase – chromosome replication (S = synthesis = “to make”)

G2 phase – molecules and organelles required for cell division produced

M phase – mitosis and cytokinesis

Interphase – G1, S, G2

S phase

G1 phase

G2 phase

CELL DIVISION

Eukaryotes (cells with a nucleus) go through 2 stages of division Mitosis – division of the nucleus Cytokinesis – division of the

cytoplasm

MITOSIS

4 phases of nuclear division

Prophase Longest phase of

mitosis Chromosomes become

visible Centriole pairs begin

to separate Spindle fiber forms

(made of microtubules)

Nuclear envelope breaks down

Spindle begins to attach to chromosomes at the centromere

Metaphase

Chromosomes line up across center of the cell (“equator” or “metaphase plate”)

Centriole pairs at opposite ends of the cell

Centromere connected to the spindle fibers

Anaphase

Sister chromatid split apart

Chromosomes get pulled to opposite poles by the shrinking spindle fibers

Telophase Chromosomes

decondense

Nuclear envelope reforms around each set of chromosomes at opposite ends of the cell

2 nuclei are formed

Cytokinesis

Division of the cytoplasm

2 new daughter cells are formed with the same number of chromosomes as the original cell.

Video of Mitosis http://highered.mcgraw-hill.com/sites/0072437316/stu

dent_view0/chapter11/animations.html#

http://www.youtube.com/watch?v=s1ylUTbXyWU&feature=related

Name the stages…

Try This Virtual Lab

http://bio.rutgers.edu/~gb101/lab2_mitosis/section1_frames.html

Homework Online Mitosis W/S

Mitosis Flipbook. Include:

Interphase, pro-, meta-, ana-, telo-, cytokinesis

Homework Pg. 249 #1-6

Pg. 257 #13-14