Lecture 24

Question 1

Intestinal epithelial cells: replaced every –

Answer 1

few days

Question 2

Skin cells: replaced every –

Answer 2

2-4 weeks

Question 3

Hepatocytes, heart muscle cells, neurons: replaced only during –

Answer 3

healing processes

Question 4

Cancer occurs when the mechanisms that maintain these normal growth rates malfunction to cause –

Answer 4

excess cell division

Question 5

A cell with impaired abilities to control its proliferation and tissue characteristics.

Answer 5

transformed cell

Question 6

CANCER IS A – DISEASE

Answer 6

GENETIC

Question 7

Cancer results from multiple genetic changes in a –

Answer 7

single cell

Question 8

Cancer = Accumulation of mutations over lifetime:

Answer 8

late life disease

Question 9

proto-oncogenes → oncogenes (gain-of-function)

Answer 9

promote cell growth

Question 10

tumor suppressor→loss of function

Answer 10

restrain cell growth

Question 11

care-taker genes→loss of function

Answer 11

protect genome integrity (repair)

Question 12

Encode proteins that stabilize the genome

Tumors arise from both increase in point mutations and chromosome instability

Answer 12

care taker genes

Question 13

Tumor cells frequently show – (i.e. highly aberrant chromosome compliments).

Answer 13

aneuploidy

Question 14

Something in M phase cytoplasm causing G1 nuclei to enter mitosis. (induces mitosis)

Answer 14

Maturation Promoting Factor (MPF)

Question 15

MPF is a –

Answer 15

Cdk and a cyclin.

Question 16

Cells divide when cycling band decays. Cycling band called a –

Answer 16

cyclin.

Question 17

T/F: The Cdk is only active when it is bound to cyclin.

Answer 17

true

Question 18

The – of cyclin goes up and down with the cell cycle, therefore the kinase activity of Cdk also goes up and down with the cell cycle.

Answer 18

concentration

Question 19

Cdc2 kinase is a –. In yeast there are two cyclins, a G1 cyclin and a mitotic cyclin.

Answer 19

Cdk

Question 20

In yeast, a – in mitotic cyclin required to enter G1.

Answer 20

Decrease

Question 21

Retinoblastoma encodes a protein that inhibits –, required for activation of DNA synthesis machinery

Answer 21

transcription factor E2F

Question 22

Rb is a – of Cdk

Answer 22

target

Question 23

Cyclins and CDKs are –

Answer 23

proto-oncogenes

Question 24

Mutation of cyclins can lead to – expression of cyclins, resulting in kinases that are always active

Answer 24

constant

Question 25

Other mutations can lead to CDKs that are active --

Answer 25

without cyclin

Question 26

Mutations of -- can stimulate constant DNA synthesis and mitosis

Answer 26

proto-oncogenes

Question 27

Growth factors are -- that stimulate cells to divide

Answer 27

mitogens

Question 28

RAS is a G-protein that kinase cascade so RAS is a --

Answer 28

proto-oncogene

Question 29

All cancer cells acquire same six characteristics | Ability to proliferate without --

Answer 29

external signal

Question 30

All cancer cells acquire same six characteristics | Fail to sense signals that -- cell division

Answer 30

restrict

Question 31

All cancer cells acquire same six characteristics | -- replicative potential

Answer 31

limitless

Question 32

All cancer cells acquire same six characteristics | change their - to other cells

Answer 32

attachment

Question 33

All cancer cells acquire same six characteristics | obtain a -- as they grow larger

Answer 33

blood supply

Question 34

All cancer cells acquire same six characteristics | tissue invasion and --

Answer 34

metastasis

Question 35

T/F: there are various pathways to cancer

Answer 35

true

Question 36

Some cancers are inherited Heterozygous for mutant allele Good allele is --, leading down the road to cancer

Answer 36

lost

Question 37

familial retinoblastoma -- eye tumors

Answer 37

many

Question 38

sporadic retinoblastoma -- eye tumors

Answer 38

one

Question 39

loss of heterozygosity through -- and --

Answer 39

nondisjunction and mitotic recombination

Question 40

Effectors that can Inhibit Cell Cycle Machinery | -- (induces DNA damage in a cell)

Answer 40

Ionizing irradiation

Question 41

Inhibits the kinase activity of the G1 cdk and prevents cells from entering into S.

Answer 41

p21

Question 42

mutations can be found in 50% of human cancers.

Answer 42

p53

Question 43

X-ray damages DNA → P53 is stabilized when DNA is damaged by phosphorylation = active p53 -->

Answer 43

production of p21

Question 44

Retinoblastoma is a -- gene

Answer 44

tumor-suppressor

Question 45

pass if cell size is adequate and chromosome replication is successfully completed

Answer 45

G2 checkpoint

Question 46

pass if all chromosomes are attached to mitotic spindle

Answer 46

metaphase checkpoint

Question 47

pass if cell size is adequate, nutrient availability is sufficient, and growth factors (signals from other cells) are present

Answer 47

G1 checkpoint

Question 48

pass if DNA replication is complete and has been screened to remove base-pair mismatch or error

Answer 48

S-phase checkpoint