Chapter 12

Question 1

What is cancer?

Answer 1

Uncontrolled cell division. Cancer cells are clonal descendants from one singular mutant cell

Question 2

Two forms of cancer

Answer 2

Sporadic: caused by a gradual accumulation of mutations. At least two are required. Accounts for majority of cancers.

Inherited: one mutant allele is inherited from one parent, and the second normal allele eventually mutates causing cancer. Rare.

Question 3

Two classes of cell cycle regulatory genes that are normally involved in cancer

Answer 3

Tumor suppressor genes: turn off or slow down cell division. Normally a loss of function mutation is what leads to cancer. Mutation is recessive so there has to be two mutations to trigger cancer cell. Unmethylated

Proto-oncogenes: turns on or speeds up cell division. Normally a gain of function mutation is what leads to cancer. Mutation is dominant and only one mutation is needed. Methylated.