Part 8: Cell Cycle

Draw the Cell Cycle

what does each stand for?

M = Mitosis: Cell Division

G1 = 1st growth phase

S = Synthesis (of DNA & RNA)

G2 = 2nd growth phase

Different cells have different ____rates

1. mitosis

2. G1

3. Synthesis

4. G2

1. mitotic

The different in the mitotic rates of different cells is characterized by a difference in the length of which phase?

G1 phase (i.e. this phase varies)

True or False: The radiosensitivity of the cell varies depending on what part of the cell cycle it is on.

True

In what phase of the cell cycle are cells the most radiosensitive? Why?

Mitosis- Cell is using all of its energy to divide → no energy to repair itself

In what phase of the cell cycle are cells the most radioresistant (i.e. least radiosensitive)?

late part of the S phase

Why are we more likely to catch a cancer cell in the M phase than a regular cell?

Cuz cancer cells reproduce more rapidly

In relation to the cell cycle, what is another reason we fractionate treatments?

to increase the likelihood of targeting cancer cells when they are in the M phase (the most radiosensitive phase)

List the 5 phases of mitosis

1. interphase

2. prophase

3. metaphase

4. anaphase

5. telophase