Download Cancer and the Cell Cycle

Chromosomes & Chromatids
 Eukaryotic DNA must be tightly coiled to fit inside a
cell (each of your cells contains six feet of it!)
 Chromatin is formed when DNA is wrapped around
protein spools
 Chromosomes form when chromatin is supercoiled
Chromatin
Chromosomes
Chromosomes & Chromatids
Before S phase, each chromosome is made of one
DNA molecule called a chromatid
After S phase (DNA is copied), each chromosome
consists of two identical DNA molecules called
sister chromatids
PHASES OF MITOSIS (PMAT)
Prophase
Metaphase
Anaphase
Telophase
Mitosis is a part of cell division where the nucleus
divides
PMAT
“Prepare”
Mitosis consists of four phases. The first is…
1. Prophase
• Chromatin condenses into chromosomes
• Nucleolus and nuclear membrane disappear
• Centrioles move towards poles of cell and start to form
spindle fibers
Interphase
Prophase
PMAT
2. Metaphase
PMAT
“Middle”
• Chromosomes align at the equator of the cell
• Spindle fibers attach to the centromere of each
chromosome
Metaphase
3. Anaphase
PMAT
“Apart/
Away”
• Spindle fibers pull centromeres apart
• Sister chromatids are pulled towards poles of cell
Anaphase
4.Telophase
PMAT
“Two”
• Chromatids reach the poles
• Nuclear membranes reform around new
nuclei
Telophase
CYTOKINESIS
Cytokinesis is the
part of cell
division where
the cytoplasm and
cell membrane
divide
Cytokinesis
It pinches the cell in two, separating membrane,
cytoplasm, and nuclei