Unit 13

Question 1

Cancer:

Answer 1

uncontrolled growth and division of cells

Question 2

Oncogenes are genes which

Answer 2

when mutated or overactivated drive a cell towards uncontrolled growth (gain of function mutations).

Question 3

Oncogenes are genes which when mutated or overactivated drive a cell towards uncontrolled growth (gain of function mutations). The normal gene is called a __ and the mutated form is called an oncogene

Answer 3

protooncogene

Question 4

The proto-oncogene normally promotes

Answer 4

cell growth

Question 5

A proto-oncogene can be converted into an oncogene by three main mechanisms:

Answer 5

1. Mutation of the DNA to an
   activated form
2. Duplication of the gene to lead to a
   higher amount of the protein
3. Chromosome rearrangement to
   alter the expression of the gene and result in a higher amount of the protein

Question 6

Tumour suppressors are genes which when mutated to a non active form;

Answer 6

drive the cell towards uncontrolled growth

Question 7

tumour repressors normally:

Answer 7

restrain cell growth

Question 8

First tumour suppressor gene discovered was

Answer 8

Rb

Question 9

First tumour suppressor gene discovered was Rb. Others include

Answer 9

BRCA1 and p53.

Question 10

Oncogenes act

Answer 10

dominantly (only a single copy of the oncogene is necessary for the cell to become cancerous).

Question 11

Oncogenes act dominantly (only a single copy of the oncogene is necessary for the cell to become cancerous). In contrast,

Answer 11

both copies of tumor suppressor genes must be mutated for cancer to develop.