Chapter 21a

Question 1

all forms of cancer share one characteristic

Answer 1

uncontrollable cell division

Question 2

tumor or neoplasm

Answer 2

abnormal growth of cells can form a mass of tissue

Question 3

benign tumor

Answer 3

an abnormal mass of tissue that usually remains at the site where it forms

Question 4

a benign tumor can be harmful when

Answer 4

they interfere with the functioning of nearby tissues or inoperable (as may occur in the brain)

Question 5

malignant tumor

Answer 5

those that can invade surrounding tissue and spread to multiple locations throughout the body; cancerous

Question 6

metastasis

Answer 6

the spread of cancer cells from one part of the body to another

Question 7

dysplasia

Answer 7

term used to describe the changes in shape, nuclei, and organization within tissues of precancerous cells (large irregularly shaped nuclei that contain increased amount of DNA)

Question 8

carcinoma in situ

Answer 8

“cancer in place”

Question 9

once cancer cells have left the original tumor they usually enter the __________ or _________ system

Answer 9

cardiovascular; lymphatic

Question 10

cells of malignant tumor:

Answer 10

• attract a blood supply
• gain the ability to leave the other cells
• spread to distant sites (metastasize)

Question 11

cancer cells:

Answer 11

• are greedy
• they deprive normal cells of nutrients weakening them
• can prevent cells from performing their usual functions
• can block blood vessels or air passageways
• can press on vital nerve pathways in the brain

Question 12

tumor suppressor genes

Answer 12

• detect damage
• manage cell repair
• cell death

Question 13

oncogenes

Answer 13

cancer-promoting genes

Question 14

Cancer can also result if _____-_________ ____ are turned off or if ________ are turned on

Answer 14

tumor- suppressor genes; oncogenes

Question 15

two types of genes usually regulate cell division:

Answer 15

proto-oncogenes; tumor suppressor genes

Question 16

proto-oncogenes stimulate

Answer 16

cell division

Question 17

tumor-suppressor genes ______ cell division

Answer 17

inhibit

Question 18

p53

Answer 18

the tumor-suppressor gene that produces a protein that regulates another gene whose job it is to make a protein that keeps cells in a nondividing state

Question 19

mutant p53

Answer 19

an important factor in more than half of all cancers; fails to halt cell division and initiate cell death

Question 20

BRCA1 and BRCA2 proteins

Answer 20

Initiate DNA repair. Two tumor-suppressor gene products that play a role in breast cancer.

Question 21

ras gene

Answer 21

product normally signals the presence of a growth factor, which stimulates cell division.

Question 22

contact inhibition

Answer 22

if healthy cells contact a neighbor they stop dividing

Question 23

apoptosis

Answer 23

programmed cell death; when DNA damage is too extensive to repair

Question 24

cancer cells often fail to trigger ______

Answer 24

apoptosis

Question 25

senescence

Answer 25

nondividing state

Question 26

telomeres

Answer 26

pieces of DNA at the tips of chromosomes that serve as counting mechanisms that limit the number of times a cell can divide

Question 27

telomerase

Answer 27

the enzyme that constructs telomeres

Question 28

when a tumor reaches the size of about a million cells its growth will stop unless it can attract a _____ ______ to deliver the ________ it needs and to remove ______.

Answer 28

blood supply; nutrients; waste

Question 29

cells produce a protein that prevents new blood vessels from forming in tissues

Answer 29

p53

Question 30

normal cells are “glued” in place by special molecules on their surfaces called

Answer 30

cellular adhesion molecules CAMs

Question 31

unanchored cancer cells can continue dividing and evade self-destruction because…

Answer 31

their oncogenes send a false message to the nucleus saying that the cell is properly attached.

Question 32

body defense cells

Answer 32

natural killer cells and cytotoxic T cells

can recognize changes to identification proteins on cell membrane when they become cancerous

Question 33

multiple ________ must occur and accumulate in a cell before the cells becomes cancerous

Answer 33

mutations

Question 34

epigenome

Answer 34

network of chemical tags that bind to DNA and turn specific genes on or off without altering the sequence of nucleotides

Question 35

mutations

Answer 35

changes in the sequence of nucleotides

Question 36

Gene ________ and _________ interact to cause cancer

Answer 36

mutations and epigenetics

Question 37

cancer risk factors

Answer 37

• viruses -tobacco use
• chemicals -carcinogens
• radiation -genetics
• age -hormones, synthetic hormones
• poor diet -lack of physical activity
• sunlight