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mastering biology 11.15-11.18

question

Which of the following statements about proto-oncogenes is false? a.) Proto-oncogenes are normal genes with the potential to become oncogenes. b.) Many proto-oncogenes code for growth factors. c.) If a proto-oncogene’s gene product is produced in smaller quantities, a cell may become cancerous. d.) A mutation must occur in a cell’s DNA for a proto-oncogene to become an oncogene.
answer

c.) If a proto-oncogene’s gene product is produced in smaller quantities, a cell may become cancerous.
question

Which of the following is not a factor that contributes to normal cells becoming cancerous? a.) the production of more effective tumor-suppressor gene products b.) excessive replication of proto-oncogenes c.) damage to a tumor-suppressor gene d.) the conversion of a proto-oncogene to an oncogene
answer

a.) the production of more effective tumor-suppressor gene products
question

In thinking about their role in cell division, oncogenes are like the ________ of a car, while tumor suppressor genes are like the ________ of a car. a.) gas pedal;brakes b.) steering wheel;brakes c.) brakes;gas pedal d.) gas pedal;headlights
answer

a.) gas pedal;brakes
question

A gene that can cause cancer when present in a single copy in a cell is called a/an a.) oncogene b.) carcinogen c.) proto-oncogene d.) enhancer gene
answer

a.) oncogene
question

Mutations in the proto-oncogene ras and the tumor suppressor gene p53 a.) increase protein synthesis by the cell. b.) can improve the chance of avoiding cancer as one ages. c.) disrupt normal regulation of the cell cycle. d.) can enhance further mutations, which can develop into cancer.
answer

c.) disrupt normal regulation of the cell cycle.
question

Cancer of the colon is caused by a.) a diet high in fiber and low in fat b.) several somatic cell gene mutations c.) a physical rupture of the colon d.) a single somatic cell gene mutation
answer

b.) several somatic cell gene mutations
question

Melanoma (skin cancer) can develop after several mutations occur in skin cells. If a woman is diagnosed with melanoma and becomes pregnant, what are the chances that her offspring will inherit melanoma? a.) The offspring will certainly be born with melanoma. b.) There is a chance, but it depends on whether or not the father has melanoma. c.) There is a chance, but it depends on how serious the mother’s melanoma is. d.) It is unlikely that the offspring will be born with melanoma.
answer

d.) It is unlikely that the offspring will be born with melanoma.
question

The figure below shows a normal cell transduction pathway. If the receptor wasn’t there, which of the following is the most likely outcome? a.) Cell division will occur normally. b.) Cell division will be increased. c.) Cell division will not occur at all. d.) Cell division will be decreased.
answer

b.) Cell division will be increased.
question

Mutations in the p53 gene can lead to cancer by a.) increasing the production of growth hormones, which trigger faster cell cycles. b.) promoting the expression of mRNA that can interact with DNA, resulting in new mutations. c.) causing the production of a faulty protein that is no longer able to inhibit cell division. d.) causing the production of excessive amounts of relay proteins.
answer

c.) causing the production of a faulty protein that is no longer able to inhibit cell division.
question

_____ is a carcinogen that promotes colon cancer. a.) fat b.) UV light c.) estrogen d.) a virus e.) testosterone
answer

a.) fat
question

The development of colon cancer occurs slowly, and colon cancer is more frequently seen in the elderly than the young. This is most likely because a.) usually six or more somatic mutations must occur to give rise to the cancer, which takes time. b.) cancer cells have to wait until new blood vessels grow into the area, which takes much time. c.) most cancer mutations interfere with mitosis, so cell division occurs more slowly. d.) cancer cells don’t have mitochondria, so they grow slowly.
answer

a.) usually six or more somatic mutations must occur to give rise to the cancer, which takes time.
question

A cell is expressing the mutant form of ras, but one of the downstream relay proteins is not present because of another mutation. How will cell division be affected in this scenario? a.) Cell division will decrease because the mutant form of ras decreases cell division. b.) Cell division will increase because the mutant form of ras increases cell division. c.) The cell will divide normally. d.) The cell will not divide at all unless other proteins that stimulate cell division are present.
answer

d.) The cell will not divide at all unless other proteins that stimulate cell division are present.
question

Which of these is NOT a carcinogen? a.) testosterone b.) cigarette smoke c.) fat d.) UV light e.) all of the above are carcinogens
answer

e.) all of the above are carcinogens
question

A cell has a mutation in both alleles of its p53 gene that causes the p53 protein to be three times as effective as normal. What do you predict would happen to this cell? a.) The cell would divide with mutated DNA and would lead to cancer. b.) The cell would divide into six daughter cells instead of two and would lead to cancer. c.) The cell would divide three times as fast and would lead to cancer. d.) The cell would divide normally or possibly not at all.
answer

d.) The cell would divide normally or possibly not at all.
question

The carcinogen known to cause the most cases and types of cancer is a.) ultraviolet light. b.) tobacco. c.) X-rays. d.) alcohol.
answer

b.) tobacco
question

Which of the following statements regarding cancer risk factors is false? a.) X-rays and ultraviolet radiation are two of the most potent carcinogens. b.) Factors that alter DNA and make cells cancerous are called carcinogens. c.) Eating 20-30 grams of plant fiber daily and reducing the intake of animal fat can reduce your risk of developing colon cancer. d.) Mutagens are usually not carcinogens.
answer

d.) Mutagens are usually not carcinogens.
question

In 2013, an estimated 160,000 people in the United States will die of lung cancer. If the cancer death rate is expected to increase by 1% per decade, approximately how many people will die of lung cancer in the United States in 2033? a.) 194,000 b.) 160,000 c.) 163,000 d.) 176,000
answer

c.) 163,000