Question

HELP?!?! PLEASE RESPOND ASAP!

Normal cells become cancer cells when?

A) cells do not respond to checkpoints
B) cells pass through G1
C) cells respond to control mechanisms
D) regulation of cell growth and division occurs

Answer 1

I believe the answer is A. If they don't respond to checkpoints they may replicate without regard to the usual control mechanisms. The rest of the answers are all what normally reproducing cells do.

Answer 2

Cancer occurs when cells replicate or grow out of control, invading nearby tissues and organs or spreading to other parts of the body. It represents a failure of the mechanisms that control or regulate cell growth or division. For more information, see http://en.wikipedia.org/wiki/Cell%20cycle%20checkpoint