The sample exam questions provided are derived from the 2004 and 2005 Recertification examinations.  Not all question categories are represented, largely because those exams contained more than 50% of Type B questions, which are no longer being used on certification examinations.  Happy practiciing, and good luck!

PART B SAMPLE QUESTIONS

1. Which of the following leads to deposition of oxalate crystals in the urinary tract?
A) Dieffenbachia (dumbcane)
B) propylene glycol
C) methoxyflurane
D) philodendron
E) ethylene glycol

2. A target organ of streptomycin-induced toxicity is
A) lung
B) heart
C) reproductive system
D) kidney
E) liver

3. Which of the following is characteristic of a nongenotoxic carcinogen?
A) has no influence on the promotional stage of carcinogenesis
B) would be expected to produce positive responses in in vitro assays for mutagenic potential
C) typically exerts other forms of toxicity and/or disrupts cellular homeostasis
D) generally shows little structural diversity
E) typically has little effect on cell turnover

4. A single large dose of N-nitrosodimethylamine fails to induce cancer in rats, but repeated dosing induces cancer because
A) the single large dose is lethal, while the threshold for cancer induction can be exceeded by repeated smaller doses
B) the main DNA lesion from a single large dose can be repaired readily by methyltransferase, while repeated smaller doses can deplete the available repair enzyme, induce mutations in DNA, and effectively induce cancer
C) the enzyme system involved in detoxification of N-nitrosodimethylamine is depleted after repeated doses, allowing N-nitrosodimethylamine to build up and exceed the threshold for cancer induction
D) the enzyme system involved in conversion of N-nitrosodimethylamine to the active carcinogen is induced and on subsequent repeated doses more active carcinogen is produced
E) the initial dose of N-nitrosodimethylamine causes cell damage and, thus, high mitotic rates; subsequent small doses induce mutations in DNA and effectively induce cancer

5. Based on the available data, cyclosporin A-induced cholestasis is most likely explained by which of the following?
A) interaction with the cytoplasmic receptor, cyclophilin
B) inhibition of transcription of message (mRNA) for critical cytokines
C) induction of programmed cell death in centrilobular hepatocytes
D) inhibition of ATP-dependent transporter(s) in the bile canalicular membrane
E) depolarization of the mitochondrial membrane potential

6. In regard to chemically-induced adverse effects on the eye,
A) no chemical has been shown to cause glaucoma
B) nonionic detergents damage the eye more that cationic detergents
C) 2,4-dinitrophenol, corticosteroids and naphthalene are known to cause cataracts in humans
D) methanol produces blindness by rendering the cornea and lens opaque
E) acids usually produce late-appearing ocular toxicity as contrasted to alkalis which produce immediate damage

7. Allergic contact dermatitis is
A) a non-immune response caused by a direct action of an agent on the skin
B) an immediate type I hypersensitivity reaction
C) a delayed type IV hypersensitivity reaction
D) characterized by the intensity of reaction being proportional to the elicitation dose
E) not involved in photo-allergic reactions

8. Which of the following is the correct xenobiotic:toxicity pair?
A) adriamycin : tubular proteinuria
B) polyvinyl alcohol : disseminated intravascular coagulation
C) hydralazine : renal papillary necrosis
D) maleic acid : mesangial fibrosis
E) gold : glomerulonephritis

9. The primary site of kidney damage resulting from acute exposure to inorganic mercury salts is the
A) glomerulus
B) proximal tubule
C) loop of Henle
D) renal papilla
E) entire nephron

10. The fertility index
A) is calculated as (number of pups alive at 4 days/number of pups born alive) x 100
B) represents the number of live fetuses per liter x 100
C) represents the percent of copulations that result in pregnancies
D) is calculated as (number of fetuses at 14 days/total number of implantations) x 100
E) can be calculated as early fetal deaths/total implantations x 100

11. Which substance has been identified as a respiratory tract carcinogen in humans?
A) kaolin
B) hydrogen fluoride
C) arsenic
D) cotton dust
E) vanadium

12. Chloracne is associated with
A) prominent hyperkeratosis of the follicular canal
B) production of excessive sebum
C) exposure to halogenated aliphatic hydrocarbons
D) exposure to chlorine gas
E) increases in serum androgen levels

13. Which of the following statements is NOT true?
A) arsenic, benzene and vinyl chloride are known human carcinogens
B) many peroxisome proliferators cause hepatic tumors in rats and are promoting agents for hepatocarcinogenesis
C) benzidine, beta-naphthylamine, and derived dyes have caused urinary bladder tumors in exposed workers
D) short asbestos fibers (<2 um long) are thought to be predominately responsible for the induction of mesotheliomas
E) butylated hydroxyanisole (BHA) acts as a nonmutagenic carcinogen in the forestomach of rats

14. Which of the following assumptions is NOT correct regarding risk assessment for male reproductive effects in the absence of mechanistic data?
A) an agent that produces an adverse reproductive effect in experimental animals is assumed to pose a potential reproductive hazard to humans
B) in general, a non-threshold is assumed for the dose-response curve for male reproductive toxicity
C) effects of xenobiotics on male reproduction are assumed to be similar across species unless demonstrated otherwise
D) the most sensitive species should be used to estimate human risk
E) reproductive processes are similar across mammalian species

15. Acidic drugs accumulate in the fetus because of which of the following?
A) ion trapping due to reduced intracellular pH in the fetus
B) decreased levels of alpha 1-acid glycoproteins in the fetus
C) placental transport systems favor accumulation in the fetus
D) fetal hepatic uptake and biliary excretion develop early in gestation
E) fetal albumin exhibits a higher affinity than adult albumin

16. The most serious consequence of crude oil or kerosene ingestion by cattle is
A) liver damage
B) kidney damage
C) aspiration pneumonia
D) central nervous system stimulation
E) leukemia

17. Toxic injury to the cell body, axon and surrounding Schwann cells of peripheral nerves are referred to, respectively, as
A) neuropathy, axonopathy and myelopathy
B) neuronopathy, axonopathy and myelinopathy
C) neuropathy, axonopathy and gliosis
D) neuronopathy, dying-back neuropathy and myelopathy
E) chromatolysis, axonopathy and gliosis

18. The conceptus is considered preferentially vulnerable to chemical insult due to all of the following EXCEPT
A) rapid rate of cell proliferation
B) requirement for precise temporal and spatial localization of cells and cell products C) rapid blood flow (heart rate) and increased tissue distribution of the chemical
D) limited drug metabolism capability
E) immaturity of the immune system

19. Which of the following is a nongenotoxic liver carcinogen in rats?
A) aflatoxin
B) vinyl chloride
C) pyrrolizidine alkaloids
D) clofibrate
E) tamoxifen

20. Suppression of NK (natural killer) cell activity produces adverse effects in animals because
A) NK cells play a role in the immune surveillance of tumors and the inhibition of metastases
B) NK cells are precursors to pulmonary macrophages, and suppression of activity results in a decreased ability to combat pulmonary infections
C) NK cells function as a helper cell in erythropoiesis, and suppression of NK cell activity results in anemia
D) NK cells function in the complement-fixation cascade, and reduced NK cell activity causes loss of blood clotting
E) NK cells function directly by phagocytosis of pathogens to protect the host from pathogenic bacteria (acquired cell-mediated immunity)

PART B ANSWERS

1. E
2. D
3. C
4. B
5. D
6. C
7. C
8. E
9. B
10. C
11. C
12. A
13. D
14. B
15. A
16. C
17. B
18. C
19. D
20. A