Chapter 18.5

Question 1

Cancer results from

Answer 1

genetic changes that affect cell cycle control

Question 2

The gene regulation systems that go wrong during cancer are the very same systems involved in

Answer 2

embryonic development

Question 3

Cancer can be caused by

Answer 3

mutations to genes that regulate cell growth and division

Question 4

Tumor viruses can cause cancer in

Answer 4

animals including humans

Question 5

Oncogenes are

Answer 5

cancer-causing genes.

bad genes. don’t want oncogenes

Question 6

Proto-oncogenes are

Answer 6

the corresponding normal cellular genes that are responsible for normal cell grown and division.

(good genes)

Question 7

Conversion of a proto-oncogene to an oncogene can lead to

Answer 7

abnormal stimulation of the cell cycle, (then they divide a lot and turn into cancer)

Question 8

Tumor-suppressor genes help

Answer 8

prevent uncontrolled cell growth

good genes. they stop us from having tumors

Question 9

Mutations that decrease protein products of tumor-suppressor genes may contribute to

Answer 9

cancer onset

Question 10

Tumor-suppressor proteins

Answer 10

• Repair damaged DNA
• Control cell adhesion
• Inhibit the cell cycle in the cell-signaling pathway

Question 11

Mutations in the ras proto-oncogene and p53 tumor-suppressor gene are

Answer 11

common in human cancers

Question 12

Mutations in the ras gene can lead to

Answer 12

production of a hyperactive Ras protein and increased cell division

Question 13

Suppression of the cell cycle can be important in the case of

Answer 13

damage to a cell’s DNA; p53 prevents a cell from passing on mutations due to DNA damage

Question 14

Mutations in the p53 gene prevent

Answer 14

suppression of the cell cycle

Question 15

ras

Answer 15

proto-oncogene ((and oncogene??))

Question 16

p53

Answer 16

tumor-suppressor gene

Question 17

Multistep mutations are generally needed for

Answer 17

full-fledged cancer; thus the incidence increases with age

Question 18

At the DNA level, a cancerous cell is usually

Answer 18

characterized by at least one active oncogene and the mutation of several tumor-suppressor genes

Question 19

Individuals can inherit

Answer 19

oncogenes or mutant alleles of tumor-suppressor genes

Question 20

Inherited mutations in the tumor-suppressor gene adenomatous polyposis coli are

Answer 20

common in individuals with colorectal cancer

Question 21

Mutations in the BRCA1 or BRCA2 genes are found in at least

Answer 21

half of inherited breast cancers, and tests using DNA sequencing can detect these mutations