Cell Bio Ch 20

Question 1

______ is a disease of multicellular organisms

Answer 1

cancer

Question 2

cancer occurs when ____

Answer 2

somatic cells incur mutations that prevent them from “behaving” and begin to divide uncontrollably

Question 3

two properties of cancer cells

Answer 3

1. they reproduce in defiance of normal constraints on cell growth
2. they invade and colonize territories normally reserved for other cells.

Question 4

a benign tumor

Answer 4

multiplies in one are and does spread into other types of tissue

Question 5

malignant tumor

Answer 5

a tumor that has spread into other types of tissue from the one it started in.

Question 6

metastases

Answer 6

secondary tumors derived from the cells that break off the primary tumor

Question 7

cancer classifications

Answer 7

1. carcinomas
2. sarcomas.
3. leukemias and lymphomas

Question 8

carcinomas

Answer 8

derive from epithelial cell

Question 9

sarcomas

Answer 9

derive from connective tissue or muscle cells

Question 10

leukemias and lymphomas

Answer 10

derive from white blood cells

Question 11

when most tumors are found they have about ________ cells

Answer 11

a billion

Question 12

carcinogenesis

Answer 12

the production of cancer

Question 13

mutagenesis

Answer 13

mutation in DNA

Question 14

causes of mutagenesis

Answer 14

1. radiation - x rays, radon, UV light

2. mutagens - chemicals in the environment; viruses

Question 15

carcinogenesis is usually caused by _________

Answer 15

mutagenesis

Question 16

a single mutation is ________ to cause cancer

Answer 16

not enough

Question 17

cancer is cause by

Answer 17

a progressive accumulation of random mutations

Question 18

carcinogen

Answer 18

cancer causing agent

Question 19

incidence of cancer ______ upon exposure to a carcinogen

Answer 19

increase

Question 20

multiple mutation, at least _____, are responsible for cancer

Answer 20

at least five

Question 21

Both ______ and ______ changes can lead to cancer

Answer 21

genetic

epigenetic

Question 22

genetics changes

Answer 22

modifications in the DNA sequence

Question 23

epigenetic changes

Answer 23

alter gene expression through packing of DNA or changing patterns of DNA methylation

Question 24

Many cancer cells have mutations in

Answer 24

genes involved in DNA repair or enzymes responsible for epigenetic control of gene expression

Question 25

cancer stem cells

Answer 25

are capable of indefinite self-renewal

Question 26

most cells in a tumor are not capable of

Answer 26

independently forming new tumors

Question 27

normal cell division, normal apoptosis

Answer 27

homeostasis

Question 28

cell produced from cancer stem cells, most have a ________

Answer 28

limited capacity for self-renewal

Question 29

How do cancer stem cells arise?

Answer 29

1. normal stem cells that acquire a mutation

2. a highly differentiated cell (transit amplifying cell) can acquire the capacity for prolonged self-renewal

Question 30

cancer is difficult to eradicate because:

Answer 30

all cancer stem cells must be killed in a patient

Question 31

In order to metastasize, malignant cancer cells must________

Answer 31

break free from their current environment, and survive and proliferate in a foreign environment

Question 32

tumors induce ________ or the development of new blood vessels to feed the tumor

Answer 32

angiogenesis

Question 33

cancer cells do not ct in isolation but are supported by the ______ - epithelial cells such as __________ and ___________ that help sustain the tumor.

Answer 33

stroma

fibroblasts and white blood cells

Question 34

genes that have been found to be alter in various human cancer are referred to as:

Answer 34

cancer-critical genes

Question 35

two classes of cancer critical genes

Answer 35

proto-oncogenes

tumor suppressor genes

Question 36

what should be considered a third class of cancer critical genes?

Answer 36

DNA maintenance genes

Question 37

proto-oncogenes

Answer 37

overactive or overexpressed forms of these genes promote cancer and are called oncogenes

Question 38

tumor suppressor genes

Answer 38

inactive forms of these genes contribute to cancer development

Question 39

overactivity mutations (like oncogenes) require mutation in

Answer 39

one gene

Question 40

underactivity mutations (like tumor suppressor genes) require mutation in

Answer 40

two genes

Question 41

Ways that proto-oncogenes can be made overactive

Answer 41

mutation in coding sequence, gene amplification, chromosome rearrangement

Question 42

over activity - mutation in coding sequence

Answer 42

hyperactive protein made in normal amounts

Question 43

over activity - gene amplification

Answer 43

normal protein greatly overproduced

Question 44

over activity - chromosome rearrangement

Answer 44

two types:

1. nearby regulatory DNA squence causes normal protein to be overproduced
2. fusion to an actively transcribed gene produces hyperactive fusion protein

Question 45

way sof eliminating normal Rb genes, or tumor suppressor genes

Answer 45

1. nondisjunction causes chromosome loss
2. chromosome loss then chromosome duplication
3. mitotic recombination
4. gene conversion
5. deletion
6. point mutation

Question 46

5 types of treatment for cancer

Answer 46

1. Surgical methods
2. Radiotherapy or DNA-damaging chemotherapy
3. targeted treatment
4. Block formation of the new blood vessels
5. Target products of specific oncogenes

Question 47

radio therapy or DNA-damaging chemotherapy treatment for cancer

Answer 47

cancer cells lack normal checkpoint mechanisms so they are genetically unstable and can be killed by these radio- or chemotheray

Question 48

target treatment for cancer

Answer 48

using a medication that targets a weakness in the cancerous cells that causes them to kill themselves or be unable to divide.

Question 49

block formation of new blood vessels - treatment for cancer

Answer 49

keep tumor from creating blood vessels to feed their growing needs

Question 50

color codes in DNA microarray (DNA chips)

Answer 50

red - gene amplification

green - gene loss