Mitosis

1
Mitosis

• Cell reproduction in which two identical cells
  are made from one cell

2
Resting Cell Interphase
centrioles

• Nucleus and nucleolus present
• DNA in the form of chromatin (long strings)
• DNA and centrioles replicate before mitosis
  begins.

nucleus nucleolus
3
Step 1 Prophase
chromosomes

• Chromatin shortens and thickens into chromosomes
• Nuclear membrane and nucleolus disappear
• Centrioles begin to move apart from each other
• Spindle fibers begin to form between the two
  centrioles.

nuclear membrane disappears
4
Chromosome vs. Chromatin
chromatin
chromosome
5
Step 2 Metaphase

• Centrioles at opposite ends of cell with fibers
  between
• Sister chromatids attached to fibers at the
  centromere and lined up at the equator.

equator
spindle fibers
6
Step 3 Anaphase

• Sister chromatids separate
• Now called daughter chromosomes
• Spindle fibers pull chromosomes to opposite poles

7
Step 4 Telophase

• Each end has complete set of chromosomes
• Spindle fibers disappear
• Nuclear membrane and nucleolus reappears
• Cell membrane pinches in and cytoplasm divides in
  half (cytokinesis) making two identical cells

membrane pinching
8
Daughter Cells

• Mitosis ends
• Two daughter cells
• Exact copies
• Two new cells will grow to normal size.

9
Animal PROPHASE Plant
10
Animal METAPHASE Plant
11
Animal ANAPHASE Plant
12
Animal TELOPHASE Plant
CELL PLATE
13
Prokaryotic Cell Division