Mitosis and the Cell Cycle

1
Mitosis and the Cell Cycle

• Cell reproduction

2
Discussion Questions

1. What are the two main phases that occur during
   the cell cycle?
2. What are Interphase, Mitosis, and Cytokinesis?
3. Why is Interphase so important?
4. Create a unique mneumonic device to remember what
   occurs during each step of Mitosis.
5. How is Cytokinesis different in plant cells and
   animal?
6. Create a question about this topic that you dont
   know.

3
The Cell Cycle

• The sequence of growth and division of a cell.
• 95 of cell cycle in interphase
• 5 of cell cycle in mitosis

4
Animated Mitosis Cycle

• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase Cytokinesis

5
Cell Cycle
6
Interphase occurs before mitosis begins

• Chromosomes are copied ( doubles)
• Chromosomes appear as threadlike coils
  (chromatin) at the start, but each chromosome and
  its copy(sister chromosome) change to sister
  chromatids at end of this phase

CELL MEMBRANE
Nucleus
Cytoplasm
7
Interphase
Plant Cell
Animal Cell
Photographs from http//www.bioweb.uncc.edu/biol1
110/Stages.htm
8
Prophase 1st step in Mitosis

• Mitosis begins (cell begins to divide)
• Centrioles (or poles) appear and begin to move to
  opposite end of the cell.
• Spindle fibers form between the poles.

Centrioles
Sister chromatids
Spindle fibers
9
Prophase
Plant Cell
Animal Cell
Spindle fibers
Centrioles
Photographs from http//www.bioweb.uncc.edu/biol1
110/Stages.htm
10
Metaphase 2nd step in Mitosis

• Chromatids (or pairs of chromosomes) attach to
  the spindle fibers.

Centrioles
Spindle fibers
11
Metaphase
Plant Cell
Animal Cell
Photographs from http//www.bioweb.uncc.edu/biol1
110/Stages.htm
12
Anaphase 3rd step in Mitosis

• Chromatids (or pairs of chromosomes) separate and
  begin to move to opposite ends of the cell.

Centrioles
Spindle fibers
13
Anaphase
Plant Cell
Animal Cell
Photographs from http//www.bioweb.uncc.edu/biol1
110/Stages.htm
14
Telophase 4th step in Mitosis

• Two new nuclei form.
• Chromosomes appear as chromatin (threads rather
  than rods).
• Mitosis ends.

Nuclei
Nuclei
Chromatin
15
Telophase
Plant Cell
Animal Cell
Photographs from http//www.bioweb.uncc.edu/biol1
110/Stages.htm
16
Cytokinesisoccurs after mitosis

• Cell membrane moves inward to create two daughter
  cells each with its own nucleus with identical
  chromosomes.

17
Animal Mitosis -- Review
Interphase                                                              Prophase                                                             
Metaphase                                                              Anaphase                                                             
Telophase                                                              Interphase                                                             
18
Plant Mitosis -- Review
Interphase                                                              Prophase                                                             
Metaphase                                                              Anaphase                                                             
Telophase                                                              Interphase                                                             
19
Remembering the steps in mitosis.

• https//www.youtube.com/watch?v-PMXatafIXc
• I - not very "I"nteresting. P - chromosomes
  first a"P"pear M - chromosomes line up in
  "M"iddle A - they move "A"way T - you have
  "T"wo (in mitosis) 
• I Played My Accordion Today.

20
Cell Cycle and Mitosis Research Questions

1. What are the two main parts of the cell cycle?
2. Describe the state of a cell about to start
   mitosis
3. How is the genetic material in two daughter cells
   similar to the genetic material in a parent cell?
4. Describe in order the steps that occur during
   mitosis and cytokinesis and their major changes
   that occurs.
5. How is cytokinesis in plant cells similar to
   cytokinesis in animal cell? How is it different?

21
Answers

1. Interphase and Mitosis are the two main parts of
   the cell cycle
2. Before Mitosis the cell is in interphase and is
   in the process of copying the DNA and making
   extra organelles for both cells.
3. In the parent cell the genetic information is
   copied and the daughter cells receive a full set
   of the same DNA.

22
Answers

• 4) Interphase DNA is copied and organelles
  produced
• Prophase Centrioles and spindle fibers form.
  Centrioles move to poles
• Metaphase DNA line up in middle of cell and
  spindle fibers attach to centrioles and DNA.
• Anaphaase The DNA is pulled to different sides
• Telophase New nuclei form around the DNA.
• Cytokinesis The membranes in an animal splinch
  off forming two cells. In plant cells a new cell
  wall forms in the middle of the parent cell
  dividing the daughter cells.

23
Answers

• 5) Both plant and animal cells go through
  cytokinesis which is the process by which the
  cell membrane/wall separate the cytoplasm forming
  two new cells. They are different because in an
  animal cell the cell membrane splinch off forming
  two cells. In plant cells a new cell wall forms
  in the middle of the parent cell dividing the
  daughter cells.