1. The Cell Cycle

4. Interphase Divided into 3 phases: G1, S, and G2
During G1 the cell is growing and maturing; if the cell will never divide, it will spent its life here (known as G0)
During S, the DNA replicates
During G2 the cell prepares for the division (makes proteins, etc.)

5. Mitosis Mitosis is divided into 4 phases:
prophase, metaphase, anaphase, and telophase
You can remember interphase, prophase, metaphase, anaphase, and telophase by IPMAT

6. Prophase Nuclear membrane breaks down
Chromatin condenses into individual chromosomes (scattered throughout the cell)
Centrioles (in animal cells) begin to migrate to the poles
Spindles form and grow toward the cell’s center (equator)

9. Metaphase
Spindle fibers connect to the centromere of each sister chromatid
The spindle fibers pull the chromosomes to the metaphase plate or equator (the middle of the cell)

13. Anaphase
The spindle fibers pull at the sister chromatids to separate them at the centromere
Chromatids (now single stranded chromosomes) are pulled toward opposite ends of the cell (the poles)

17. Telophase
A nuclear membrane forms around each set of single stranded chromosomes
The chromosomes become long, stringy, and less distinct to reform chromatin
Spindle fibers break down
Telophase often overlaps with cytokinesis

22. Cytokinesis
Once the nuclear material is divided, the remainder of the cell divides during cytokinesis
In plant cells, a cell plate forms from vesicles that bud off the Golgi and will become a new cell wall
In animal cells, the cell membranes pinch in to form a cleavage furrow

26. What happens with the cell cycle isn’t regulated?
Internal signals within the cell can turn cell division off and on
Cells can detect the presence or absence of certain chemicals produced within the cell

27. External signals can also turn cell division off and on
External signals are chemicals from outside the cell that the cell can detect

28. A checkpoint is a critical point in the cell cycle where chemical signals can regulate the cycle

30. Cancer is caused from a fault in controlling the cell cycle
Cancer begins when a single cell divides uncontrollably
Usually the human immune system will recognize the cell and destroy it

31. If a cell continues to divide, it creates a mass of abnormal cells called a tumor
Tumors can either be:
malignant which impairs the function of
organs and may move to other organs
benign which do not spread