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 primary role of dietary guidelines?

A. To ensure that all food groups are consumed in appropriate proportions.
B. To prevent chronic diseases and promote overall well-being.
C. To help individuals meet their nutritional needs while reducing the risk of chronic disease.
D. To offer specific recommendations for the intake of nutrients that support health.

Correct answer: C

Rationale: The correct answer is C: 'To help individuals meet their nutritional needs while reducing the risk of chronic disease.' Dietary guidelines are designed to provide guidance on the types and amounts of food that support good health and reduce the risk of chronic diseases. Choice A has been corrected to mention 'appropriate proportions' instead of 'equal amounts,' as dietary guidelines emphasize balance and variety. Choice B is partially correct, but the primary focus of dietary guidelines is on meeting nutritional needs. Choice D is incorrect because while dietary guidelines may include nutrient recommendations, their primary focus is on overall dietary patterns rather than specific nutrient intake.

3. Which characteristic is most typical of a chronic disease?

A. It has a rapid onset.
B. It rarely has noticeable symptoms.
C. It produces sharp pains.
D. It progresses gradually.

Correct answer: D

Rationale: The correct answer is D. Chronic diseases are characterized by a gradual progression over time, affecting individuals for an extended period. Option A is incorrect as chronic diseases do not have a rapid onset like acute conditions. Option B is incorrect as chronic diseases often manifest noticeable symptoms. Option C is incorrect as sharp pains are not a defining characteristic of chronic diseases. Chronic diseases can present a variety of symptoms depending on the specific condition, but gradual progression is a common feature distinguishing them from acute illnesses.

4. What should be monitored in a child with congenital adrenal hyperplasia (CAH)?

A. Blood glucose levels
B. Electrolyte balance
C. Urine output
D. Hemoglobin levels

Correct answer: B

Rationale: In a child with congenital adrenal hyperplasia (CAH), monitoring electrolyte balance is crucial. CAH can lead to adrenal insufficiency, causing imbalances in electrolytes such as sodium and potassium. Monitoring electrolyte levels helps in preventing complications like dehydration, electrolyte disturbances, and adrenal crisis. While blood glucose levels may need monitoring in other conditions like diabetes, it is not the primary concern in CAH. Urine output is important in assessing kidney function but is not a direct monitoring parameter for CAH. Hemoglobin levels are more relevant in conditions such as anemia, not specifically in CAH.

5. Which nutrient is an example of a macronutrient?

A. proteins
B. minerals
C. water-soluble vitamins
D. fat-soluble vitamins

Correct answer: A

Rationale: Proteins are indeed macronutrients as they are required by the body in larger quantities for various functions such as growth, repair, and energy production. Choice B, minerals, are micronutrients needed in smaller amounts for various physiological processes. Choices C and D, water-soluble vitamins and fat-soluble vitamins, respectively, are also micronutrients that play essential roles in the body but are not classified as macronutrients.