Catalyst

1. What structure in the cell is made up of condensed chromatin?

2. During what stage of interphase is DNA duplicated?

3. What are the two things found inside the nucleus?

4. When we are talking about mitosis, what kind of cells are we talking about?

Mitosis and the Cell Cycle

Ms. KlinkhachornFebruary 17, 2010

Interphase

• Longest phase of the cell cycle– 90% of a cell’s life spent here

• Has 3 stages:– G1– S– G2

Mitotic Phase

• Occurs after interphase• Mitosis has 4 stages:– Prophase– Metaphase– Anaphase– Telophase

• Cytokinesis

Interphase

Prophase

Prophase

• Nucleus starts to break down• Nucleolus disappears• Chromosomes formed from chromatin• Spindles start to grow and separate

Metaphase

Metaphase

• Spindles located at opposite ends of the cell – Spindle fully grown

• Chromosomes line up across the middle of the cell

• Spindle fibers (microtubules) attach to chromosomes at the centromere

Anaphase

Anaphase

• Microtubules attached to chromosomes shrink– Causes the sister chromatids to separate

• Microtubules not attached to chromosomes get longer– Causes the cell to stretch apart more

Telophase and Cytokinesis

Telophase and Cytokinesis

• Telophase– Nucleus and nucleolus reform– Chromosomes fall apart (into chromatin strands)– Spindle disappears

• Cytokinesis– This is NOT a part of mitosis, but starts during

telophase– Division of the cytoplasm

• Cells pinch inwards to form two daughter cells

End Results of Mitosis – Daughter Cells

Exit Slip

1. List the phases of mitosis in order.2. What is cytokinesis?3. Name the phase when..

• The nucleus reappears• The chromosomes move to opposite ends of the cells• The nucleolus disappears• The spindle fibers shorten and lengthen for movement• The chromosomes line up in the middle of the cell

Mitosis animations

• http://www.cellsalive.com/mitosis.htm• http://highered.mcgraw-hill.com/sites/00730

31216/student_view0/exercise13/mitosis_movie.html

• http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter11/animations.html#