What is one major weakness of a laboratory-based study?

Correct Answer: C

Rationale: One major weakness of laboratory-based studies is that results from animal testing cannot always be applied to human beings. This limitation arises due to the inherent biological differences between animals and humans, making the generalization of findings challenging. While costs may be a concern in some cases, they do not represent a universal weakness of laboratory-based studies. Findings in such studies can be replicated to ensure validity, and experimental variables can be effectively controlled in a laboratory setting. Choice C is the correct answer because the translatability of results from animal studies to humans is a significant challenge in laboratory-based research, impacting the direct application of findings to human health and well-being.

Correct Answer: D

Rationale: The correct answer is D. Controls in an experiment ensure that the subjects are similar in all respects except for the treatment being tested. This allows for a fair comparison between the treatment group and the control group. Choice A is incorrect because the size of the groups is not the primary benefit of using controls. Choice B is incorrect as blinding, not controls, refers to subjects not knowing about the experiment. Choice C is incorrect as it pertains more to randomization than the use of controls.

Correct Answer: A

Rationale: The correct answer is A: peer review. Before publication, research findings must undergo peer review, where experts in the field evaluate the validity and significance of the study. Choice B, cohort review, is incorrect as it does not involve the same level of evaluation by experts. Choice C, research intervention, is not a term used to describe the evaluation process before publication. Choice D, double-blind examination, refers to a study design where neither the participants nor the researchers know who is receiving a particular treatment, which is not the same as the peer review process.

Correct Answer: D

Rationale: The correct answer is D. Nutrient recommendations are designed to meet the needs of most healthy people, providing guidelines for a balanced diet. Choice A is incorrect because while nutrition plays a crucial role in health, it is not the only factor influencing it. Choice B is incorrect as nutrient needs vary based on factors like age, gender, activity level, and health status. Choice C is incorrect because all nutrients are essential for different bodily functions, and none can be deemed universally more important than others.

Correct Answer: B

Rationale: A positive correlation between two variables indicates that they move in the same direction. This means that as one variable increases (or decreases), the other variable also increases (or decreases). Choice A is incorrect because correlation does not imply causation; it only shows a relationship between variables. Choice C is incorrect as it describes a negative correlation where variables move in opposite directions. Choice D is incorrect as a positive correlation implies a relationship between the variables.