Series 6: Multiple choice questions (choose the best statement)
Cont'd from series 5
Exercise 1
Exercise 1
Q. 1. A toxic substance produced by biological system is specially referred to as a ------
a) toxicant
b) toxin
c) xenobiotic
d) poison
Q.2 Allergic contact dermatitis isa) 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
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
Q.3. The reference dose (RfD) is generally determined by applying which of the following default procedures?
a) an uncertainty factor of 100 is applied to the NOAEL in chronic animal studies
b) a risk factor of 1000 is applied to the NOAEL in chronic animal studies
c) a risk factor of 10,000 is applied to the NOAEL in subchronic animal studies
d) an uncertainty factor between 10,000 and 1 million is applied to the NOEL from chronic animal studies
e) multiplying the NOAEL from chronic animal studies by 100
a) an uncertainty factor of 100 is applied to the NOAEL in chronic animal studies
b) a risk factor of 1000 is applied to the NOAEL in chronic animal studies
c) a risk factor of 10,000 is applied to the NOAEL in subchronic animal studies
d) an uncertainty factor between 10,000 and 1 million is applied to the NOEL from chronic animal studies
e) multiplying the NOAEL from chronic animal studies by 100
Q.4. Which of the following concerning the use of the "benchmark dose" in risk assessment is NOT correct?
a) can use the full range of doses and responses studied
b) allows use of data obtained from experiments where a clear "no observed adverse effect level" (NOAEL) has been attained
c) may be defined as the lower confidence limit on the 10% effective dose
d) is primarily used for analyses of carcinogenicity data and has limited utility for analyses of developmental and reproduction studies that generate quantal data
e) is not limited to the values of the administered doses
a) can use the full range of doses and responses studied
b) allows use of data obtained from experiments where a clear "no observed adverse effect level" (NOAEL) has been attained
c) may be defined as the lower confidence limit on the 10% effective dose
d) is primarily used for analyses of carcinogenicity data and has limited utility for analyses of developmental and reproduction studies that generate quantal data
e) is not limited to the values of the administered doses
Q.5. Administration by oral gavage of a test compound that is highly metabolized by the liver versus subcutaneous injection will most likely result in
a) less parent compound present in the systemic circulation
b) more local irritation at the site of administration caused by the compound
c) lower levels of metabolites in the systemic circulation
d) more systemic toxicity
e) less systemic toxicity
a) less parent compound present in the systemic circulation
b) more local irritation at the site of administration caused by the compound
c) lower levels of metabolites in the systemic circulation
d) more systemic toxicity
e) less systemic toxicity
Q.6. The phrase that best defines "toxicodynamics" is the
a) linkage between exposure and dose
b) linkage between dose and response
c) dynamic nature of toxic effects among various species
d) dose range between desired biological effects and adverse health effects
e) loss of dynamic hearing range due to a toxic exposure
a) linkage between exposure and dose
b) linkage between dose and response
c) dynamic nature of toxic effects among various species
d) dose range between desired biological effects and adverse health effects
e) loss of dynamic hearing range due to a toxic exposure
Q.7. Which of the following was banned under the Delaney clause of the Food Additive Amendment of 1958?
a) butylated hydroxytoluene
b) sulfamethazine
c) cyclamate
d) phytoestrogens
e) aflatoxin
a) butylated hydroxytoluene
b) sulfamethazine
c) cyclamate
d) phytoestrogens
e) aflatoxin
Q.8. Which of the following is NOT an initiating event in carcinogenesis?
a) DNA adduct formation
b) DNA strand breakage
c) mutation of proto-oncogenes
d) oxidative damage of DNA
e) mitogenesis
a) DNA adduct formation
b) DNA strand breakage
c) mutation of proto-oncogenes
d) oxidative damage of DNA
e) mitogenesis
Q.9. Which of the following toxicity can occur due to single exposure?
a). Acute toxicity
b). Sub-acute toxicity
c). Sub-chronic toxicity
d). Chronic toxicity
Q. 10. 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
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
Answers
1, b; 2. c; 3.a; 4.d; 5a; 6.b; 7.c; 8.e; 9 a; 10. b.
Exercise 2
Q.1 Which of the following is characteristic of a non-genotoxic carcinogen?
a) has no influence on the promotional stage of carcinogenesis
b) would be expected to produce positive responses in in vitroassays 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
a) has no influence on the promotional stage of carcinogenesis
b) would be expected to produce positive responses in in vitroassays 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
Q.2. A newly formed hapten protein complex usually stimulates the formation of a significant amount of antibodies in ---------------
a) 1 to 2 min
b) 1-2 hrs
c) 1-2 days
d) 1 to 2 weeks
Q.3. Prolonged muscle relaxation after succinylchioline is an example of a/an --
a) IGE- mediated allergic reaction
b) idiosyncratic reaction
c) immune complex reaction
d) reaction related to a genetic increase in the activity of a liver enzyme
Q.4. Increased production of methemoglobin is due to decreased activity of -----
a) cytochrome P450 2B6
b) NADH cytochrome b5 reductase
c)cytochrome oxidase
d) cytochrome a3
Q.5. The most common target organ of toxicity is the ----
a) heart
b) lung
c)CNS (brain and spinal cord)
d) skin
Q.6. the organs least involved in systemic toxicity are ---
a) brain and peripheral nerves
b) muscle and bone
c)liver and kidney
d) hematopoietc system and lungs
Q.7. If two organophosphate insecticides are absorbed into an organism, the result will be----
a) additive effect
b) synergestic effect
c) potentiation
d) substraction effect
Q.9. If propyl alcohol and carbon tetrachloride are chronically absorbed into an organism, the effect on the liver would be
a) additive effect
b) synergesic
c) potentiation
d) substraction effect
10. The treatment of strychnine induced convulsions by diazepam is an example of ----
a) chemical antagonism
b) dispositional antagonism
c) receptor antagonism
d) functional antagonism
Answers
1. c: 2.d : 3.b : 4.b ; 5.c ; 6. b; 7.a ; 8.b ; 9.c ; 10. D. .
Exercise 3
Q.1. The use of antitoxin in the treatment of snakebite is an example of ------
a) dispositional antagonism
b) chemical antagonism
c) receptor antagonism
d) functional antagonism
Q.2. The use of charcoal to prevent the absorption of diazepam is an example of ----
a) dispositional antagonism
b) chemical antagonism
c) receptor antagonism
d) functional antagonism
Q.3. The use tamoxifen in certain breast cancer is an example of ---
a) dispositional antagonism
b) chemical antagonism
c) receptor antagonism
d) functional antagonism
Q.4. Chemicals known to produce dispositional tolerances are ----
a) benzene and xylene
b) trichloroethylene and methylene chloride
c) paraquat and diaquat
d) carbon tetrachloride and cadmium
Q.5. The most rapid exposure to a chemical would occur through which of the following routes-------
a) oral
b) subcutaneous
c) inhalation
d) intramuscular
Q. 6. A chemical that is toxic to the brain but which is detoxified in the liver would be expected to be ---
a) more toxic orally than intramuscularly
b) more toxic rectally than intravenously
c)more toxic via inhalation than orally
d) more toxic on the skin than intravenously
Q.7. The LD50 is calculated from ------
a) a quantal dose-response curve
b) a hormesis dose –response curve
c) a graded dose-response curve
d) a log-log dose-response curve
Q.8. A U-shaped graded toxicity dose-response curve is seen in humans with----
a) pesticides
b) sedatives
c) opiates
d) vitamins
Q. 9. The TD1 / ED99 is called-
a) margin of safety
b) therapeutic index
c) potency ratio
d) efficacy ratio
Q. 10. All of the following are reasons for selective toxicity except--------
a) transport differences between cell
b) biochemical differences between cell
c) cytology of male neurons versus female neurons
d) cytology of plant cells versus animal cells
Answers
1. b; 2. a; 3. c; 4. d; 5. c; 6. c; 7. a; 8.d ; 9. a ; 10. c.
Exercise 4
Q 1. Regulatory toxicology aims at guarding the public from dangerous chemical exposures, and depends primarily on which form of study:
a. observational human studies.
b. controlled laboratory animal studies.
c. controlled human studies.
d). environmental studies.
Q 2. Risk from a public health perspective, is best described as the following:
a. undesirable endpoint is reached.
b. a possibility of a bad outcome.
c. likelihood of an unwanted outcome combined with uncertainty of when it will occur.
d. a bad outcome is assured and its mechanism is well understood.
Q 3. Which of the following statements is true regarding risk analysis?
a. it is a field of study that has been around for the last century.
b. it was developed by the pharmaceutical companies in response to concerns over new medications.
c. it is a relatively new field of study, spurred by new technologically-based risks.
d. it was largely a private sector venture.
Q 4. Which of the following are tools used in risk analysis?
a. toxicology
b. epidemiology
c. clinical trials
d. all of the above.
Q 5. Which of the following are common end points:
a. death
b. No Observable Effect Level
c. No Observable Adverse Effect Level
d. Lowest Observable Adverse Effect Level
e. All of the above.
Q. 6. The LD50 is best described as which of the following:
a. the dose at which 50 % of all test animals die
b. the dose at which 50 % of the animals demonstrate a response to the chemical
c. the dose at which all of the test animals die
d. the dose at which at least one of the test animals dies
Q 7. The effective dose is best described as which of the following:
a. the dose at which 50 % of all test animals die
b. the dose at which some of the animals demonstrate a response to the chemical
c. the dose at which all of the animals demonstrate a response to the chemical
d. the dose at which 50 % of all test animals demonstrate a response to the chemical
Q 8. Extrapolation is best described as which of the following:
a. using known information to reach a conclusion.
b. using known information to infer something about the unknown.
c. using speculative information to infer something about the known.
d. a "best guess" approach.
Q. 9. 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
Q.10. Which of the following statements is true?
a) chemical carcinogens in animals are always carcinogens in animals
b) A chemical that is carcinogenic in humans is usually carcinogenic in at least one animal species
c) From a regulating perspective carcinogens are considered to have a threshold dose-response curve
d) Arsenic is an example of a chemical that is carcinogenic to humans and nearly all species treated.
Answers:
1. b; 2. c; 3. c; 4. d; 5. e; 6.a;7. d; 8. b; 9. b;10. c.
To be cont’d
FURTHER READING
Gupta PK (2018) Illustrative Toxicology with Question bank. 1st Edition. Elsevier, USA
Gupta PK (2016) Fundamentals of Toxicology: Essential concepts and applications. 1st Edition. ISBN-9780128054260, pp 438, BSP/Elsevier, USA
The Merck Veterinary Manual (2016). Chapter “Herbicide Poisoning” by PK GUPTA 11th edition, Merck & Co. Inc Whitehouse Station, NJ, USA 2969-99
The Merck Veterinary Manual (2016). Chapter “Pentachlorophenol Poisoning” by PK GUPTA 11th edition, Merck & Co. Inc Whitehouse Station, NJ, USA pp 3052-53
Gupta PK (2016) Essential Concepts in Toxicology. Published by PharmaMed Press (A unit of BSP Books Pvt. Ltd), Hyderabad, India pp 362.
Gupta PK (2010) Modern Toxicology, Basis of organ and reproduction toxicity. Vol 1. Published by Pharma Med Press (A unit of BSP Books Pvt. Ltd). Hyderabad, India pp 1-460.
Gupta PK (2010) Modern Toxicology, Adverse effects of xenobiotics. Vol 2, Published by PharmaMed Press (A unit of BSP Books Pvt. Ltd). Hyderabad, India pp 1-460.
Gupta PK (2010) Modern Toxicology, Immuno and clinicsal toxicology Vol 3. Published by PharmaMed Press (A unit of BSP Books Pvt. Ltd). Hyderabad, India pp 1-340.
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