The dose of toxin that is lethal to half of the population is known as..
- A. LD50
- B. L50
- C. D50
- D. LD
Correct Answer: A
Rationale: LD50 refers to the lethal dose required to kill 50% of a population, commonly used in toxicology studies.
You may also like to solve these questions
How would you design an ecologic study to investigate the following problems? How might the ecologic fallacy come into play in each situation? a. lung disease and air pollution b. birth defects and hazardous waste c. cancer and radiation leakage from a power plant
- A. Ecologic fallacy arises when group-level findings incorrectly infer individual-level relationships.
- B. Ecologic studies cannot address causality.
- C. All ecologic studies suffer from severe biases.
- D. Ecologic studies are irrelevant for public health.
Correct Answer: A
Rationale: Ecologic studies analyze aggregated data, risking incorrect inferences about individuals (ecologic fallacy).
Nepal red cross society established in
- A. 1969
- B. 1963
- C. 1965
- D. 1967
Correct Answer: B
Rationale: The Nepal Red Cross Society was founded in 1963.
Contrast the changes in death rates due to cancer, heart disease, and cerebrovascular diseases.
- A. Heart disease and cancer rates increased initially but stabilized or declined, while cerebrovascular diseases declined steadily.
- B. All three diseases showed consistent declines.
- C. Cancer rates increased, while heart disease and cerebrovascular diseases decreased.
- D. Heart disease rates increased, while cancer and cerebrovascular diseases decreased.
Correct Answer: A
Rationale: Heart disease and cancer initially rose but later stabilized or declined, while cerebrovascular diseases showed steady declines due to improved treatments and risk factor management.
What are some possible hazards associated with the organochloride pesticide DDT?
- A. Bioaccumulation and reproductive toxicity.
- B. Immediate skin irritation and respiratory distress.
- C. Increased crop yield and soil fertility.
- D. Improved water quality and biodiversity.
Correct Answer: A
Rationale: DDT bioaccumulates in ecosystems and is linked to reproductive and developmental toxicity in wildlife and humans.
Temperature is......scale
- A. Ordinal scale
- B. Interval scale
- C. Ratio scale
- D. Nominal scale
Correct Answer: B
Rationale: Temperature is measured on an interval scale because it has equal intervals but no true zero point.
Nokea