1
Name_________________________
Environmental Toxicology (ADVS 5400/6400)
Examination I
Friday, February 21, 2003
For questions 1-5, circle the letter corresponding to the correct statement(s). None, one
or more of the selections may be correct. Don’t guess--incorrect responses will be
deducted from your score (5 each).
1. The most important factor that determines chemical toxicity is:
a. potency
b. partition coefficient
c. whether chemical is converted to electrophilic intermediate
d. dose
e. pH of environment
2. The following are true statements about risk assessment:
a. reference dose is synonymous with acceptable daily intake.
b. people are generally less susceptible than animals to most toxins on a mg/kg
body weight basis
c. people are usually accepting of risks they can’t control
d. in toxicity trials, NOAEL signifies the dose at which no adverse effects are
observed
e. dose levels are often corrected between species by surface area calculations.
3. The following are true statements about cytochrome P450.
a. the “P” in cytochrome P-450 stands for “protein.”
b. does not occur in bacteria
c. heme iron requires reduction to the +2 state before substrate binding can
occur.
d. in mammalian cells, is bound to membranes called microsomes
e. catalyses reactions resulting in increased toxicity
4. The following are true statements about evaporation:
a. evaporation rate from water is directly proportional to ionization.
b. vapor pressure increases with temperature
c. if a compound is water-soluble, it will evaporate more slowly from water
compared to a less water-soluble compound.
d. ionized chemicals bind to water due to Brownian movement.
e. chemicals evaporate from wet soil more slowly than from dry soil
