Nokea
Selection bias interferes-
- A. internal validity
- B. external validity
- C. face validity
- D. all
Correct Answer: A
Rationale: Selection bias undermines internal validity by affecting the comparability of study groups.
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Identify the type of study design described: Questionnaires were mailed to every 10th person listed in the city telephone directory. Each person was asked to provide his or her age, sex, and smoking habits and to describe the presence of any respiratory symptoms during the preceding 7 days.
- A. Cohort study
- B. Case-control study
- C. Cross-sectional study
- D. Ecological study
Correct Answer: C
Rationale: This survey-based approach is characteristic of a cross-sectional study.
Standard error is measure of
- A. Conceptual error
- B. Sampling error
- C. Instrumental error
- D. Observer error
Correct Answer: B
Rationale: Standard error quantifies the precision of the sample mean as an estimate of the population mean.
Which method is suitable for teaching mother group about preparation of superflour:
- A. demonstration
- B. group discussion
- C. roleplaying
- D. exhibition
Correct Answer: A
Rationale: Demonstration is an effective method for teaching practical skills such as preparing superflour.
Discuss the possible long-term and short-term effects that farm workers may experience when they are exposed to organophosphate pesticides.
- A. Short-term: nausea, headaches; Long-term: neurological damage.
- B. Short-term: increased energy; Long-term: improved cognition.
- C. Short-term: weight gain; Long-term: enhanced immune function.
- D. Short-term: improved vision; Long-term: heightened sensory perception.
Correct Answer: A
Rationale: Organophosphates cause acute cholinergic symptoms and chronic neurological damage due to enzyme inhibition.
Acid rain due to
- A. SO2
- B. H2SO4
- C. HCL
- D. b. and c
Correct Answer: D
Rationale: Acid rain forms primarily from sulfur dioxide (SO2) and nitrogen oxides reacting with water vapor.