ETX 010 MIDTERM STUDY GUIDE QUESTIONS
AND ANSWERS WITH RATIONALES
1. Which of the following are mechanisms by which DNA mutations can arise? (Select all
that apply)
a. Exposure to benzo[a]pyrene (from tobacco smoke)
b. Random/spontaneous errors during DNA replication
c. Eating large amounts of sugar
d. Wearing synthetic fabrics
Answer: a. Exposure to benzo[a]pyrene, b. Random/spontaneous errors during DNA
replication
Rationale: Chemical mutagens (e.g., benzo[a]pyrene metabolites) form DNA adducts;
mutations also arise spontaneously from replication errors. Diet/fabrics are not direct
mutation mechanisms.
2. Which two best define cancer? (Choose two)
a. Abnormal cells dividing without control
b. Abnormal cells invading other tissues
c. Infectious disease of the lungs
d. Widespread bacterial infection
Answer: a. Abnormal cells dividing without control, b. Abnormal cells invading other
tissues
Rationale: Cancer is uncontrolled proliferation and potential invasion/metastasis.
3. Which of the following are recognized hallmarks of cancer? (Select all that apply)
a. Sustaining proliferative signaling
b. Resisting cell death (apoptosis)
c. Evading growth suppressors
d. Activating invasion and metastasis
e. Inducing aberrant angiogenesis
f. Increased hair growth
Answer: a, b, c, d, e
Rationale: These five are classic hallmarks (Hanahan & Weinberg). Increased hair is
irrelevant.
,ESTUDYR
4. Why is tumor angiogenesis beneficial to a growing tumor? (Select all that apply)
a. Provides oxygen to tumor mass
b. Provides nutrients/food to tumor mass
c. Provides a route for tumor cell metastasis
d. Causes tumor cells to die faster
Answer: a, b, c
Rationale: New blood vessels supply oxygen/nutrients and a path for metastasis; they
do not increase death.
5. Hill’s causal consideration best matching “a carcinogen metabolite binds and mutates
DNA” is:
a. Temporality
b. Biological plausibility
c. Consistency
d. Strength of association
Answer: b. Biological plausibility
Rationale: Mechanistic explanation (mutagen binding DNA) supports plausibility.
6. Which screening question(s) are most relevant when eliciting lung cancer risk history?
(Select all that apply)
a. Have you ever smoked tobacco?
b. Have you worked in shipyards or insulation removal?
c. Have you worked in chimney cleaning or home chimneys?
d. Have you ever remodeled older homes?
Answer: a, b, c, d
Rationale: Tobacco and occupational exposures (asbestos, chimney soot, remodeling
older homes with lead/asbestos) are relevant.
7. Not all carcinogens are mutagens. True or false?
a. True
b. False
Answer: a. True
,ESTUDYR
Rationale: Some carcinogens act via non-mutagenic mechanisms (e.g., hormonal
activation, chronic inflammation).
8. If a physician reports a mass is “benign,” what does that mean?
a. It is cancerous and invasive
b. It is non-cancerous and not invasive
c. It will definitely become cancerous later
d. It is infectious
Answer: b. It is non-cancerous and not invasive
Rationale: Benign masses do not invade or metastasize.
9. Hill’s consideration matching “increasing benzene exposure associated with
decreasing blood counts” is:
a. Consistency
b. Biological gradient (dose–response)
c. Analogy
d. Specificity
Answer: b. Biological gradient (dose–response)
Rationale: A monotonic relationship between exposure and effect is dose–response.
10. William Perkin’s dye produced the color:
a. Indigo
b. Mauve
c. Fuschia
d. Verdigris
Answer: b. Mauve
Rationale: Perkin discovered mauveine (mauve dye).
11. Aniline dye factory workers historically had increased risk of which cancer?
a. Lung cancer
b. Bladder cancer
c. Skin melanoma
d. Leukemia
, ESTUDYR
Answer: b. Bladder cancer
Rationale: Aromatic amines (from aniline dyes) linked to bladder cancer.
12. BASF synthesized which dye from aniline, commonly used in denim?
a. Mauve
b. Crimson
c. Indigo
d. Turquoise
Answer: c. Indigo (used to make denim)
Rationale: Aniline chemistry led to synthetic indigo used for denim dyeing.
13. When was the first plastic produced (approx.)?
a. 1600s
b. 1856
c. 1920
d. 1950
Answer: b. 1856
Rationale: Early semi-synthetic plastics date to mid-19th century (e.g., Parkesine).
14. In which industry would benzene NOT be a major expected exposure source?
a. Petrochemical plants
b. Shoe manufacturing
c. Coal processing
d. Paper mills
Answer: d. Paper mills
Rationale: Benzene is major in petroleum, solvents, shoe glue; not typically dominant in
paper mills.
15. Which is NOT a significant source of ambient benzene exposure?
a. Vehicle emissions
b. Tobacco smoke
c. Industrial emissions
d. Farming (routine field work)