how does a double blind experiment work

HESI LPN

LPN Nutrition Practice Test

1. How does a double-blind experiment work?

A. Both subject groups take turns receiving each treatment.
B. Neither subjects nor researchers know which subjects are in the control or experimental group.
C. Neither group of subjects knows whether they are in the control or experimental group, but the researchers do not know.
D. Both subject groups know whether they are in the control or experimental group, but the researchers do not know.

Correct answer: B

Rationale: The correct answer is B. In a double-blind experiment, neither the subjects nor the researchers know which subjects are in the control or experimental group. This helps to eliminate bias and ensure that the results are more objective. Choice A is incorrect as in a double-blind experiment, subjects do not take turns receiving each treatment; it is about masking the treatment allocation. Choice C is incorrect because it implies that the researchers are aware of the group allocation, which goes against the principle of blinding in a double-blind study. Choice D is incorrect as both subject groups should not know whether they are in the control or experimental group to maintain the blindness of the study.

2. What is the term for the study of how diet affects gene expression?

A. Epigenetics
B. Nutrigenomics
C. Genomics
D. Genetics

Correct answer: B

Rationale: Nutrigenomics is the study of how diet affects gene expression, influencing health outcomes and disease risk. Epigenetics (choice A) involves changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. Genomics (choice C) is the study of an organism's entire genome. Genetics (choice D) is the study of heredity and the variation of inherited characteristics.

3. How should a healthcare professional respond to a parent concerned about their child's weight gain?

A. Provide guidance on healthy eating and physical activity
B. Suggest restrictive dieting
C. Recommend increased caloric intake
D. Avoid discussing the issue

Correct answer: A

Rationale: When a parent expresses concern about their child's weight gain, the most appropriate response is to provide guidance on healthy eating and physical activity. This approach promotes healthy weight management and overall well-being. Suggesting restrictive dieting (Choice B) can be harmful, especially for children, as it may lead to unhealthy relationships with food and potential nutritional deficiencies. Recommending increased caloric intake (Choice C) without proper assessment and guidance can exacerbate the issue. Avoiding discussing the issue (Choice D) neglects a critical opportunity to address the parent's concerns and support the child's health.

4. How should a healthcare provider address the nutritional needs of a child with chronic kidney disease?

A. Increase protein intake
B. Reduce sodium and phosphorus intake
C. Promote a high-fat diet
D. Encourage frequent sugary snacks

Correct answer: B

Rationale: Reducing sodium and phosphorus intake is crucial in managing chronic kidney disease in children because it helps prevent complications such as electrolyte imbalances and bone problems. High protein intake can actually be harmful to the kidneys in this condition as it can lead to increased waste production. A high-fat diet is not recommended as it can contribute to heart and blood vessel problems. Encouraging frequent sugary snacks can lead to further complications like obesity and diabetes, which are not beneficial for a child with chronic kidney disease.

5. What is a key aspect of managing a child with eczema?

A. Daily baths with soap
B. Regular use of emollients and moisturizers
C. High-protein diet
D. Frequent exposure to sunlight

Correct answer: B

Rationale: Regular use of emollients and moisturizers is a key aspect of managing eczema in children. Emollients help maintain skin hydration and reduce irritation, which are crucial in managing eczema symptoms. Daily baths with soap can actually worsen eczema by drying out the skin further. A high-protein diet and frequent exposure to sunlight are not directly related to managing eczema and may not have a significant impact on the condition.