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 type of nutrient is needed by the body and must be supplied by foods?

A. nutraceutical
B. metabolic nutrient
C. organic nutrient
D. essential nutrient

Correct answer: D

Rationale: The correct answer is D, essential nutrient. Essential nutrients are substances that the body needs for normal functioning but cannot produce in sufficient amounts, so they must be obtained through the diet. Nutraceuticals (choice A) are products derived from food sources that are purported to provide extra health benefits beyond basic nutrition. Metabolic nutrients (choice B) and organic nutrients (choice C) are not standard terms used to describe nutrients needed by the body. Therefore, choices A, B, and C are incorrect.

3. What is an important aspect of managing a child with chronic kidney disease?

A. Monitoring electrolyte levels
B. Increasing protein intake
C. Limiting fluid intake
D. Encouraging a high-fat diet

Correct answer: A

Rationale: Monitoring electrolyte levels is crucial in managing chronic kidney disease in children because imbalances can lead to serious complications. Electrolyte levels must be carefully monitored to prevent issues such as electrolyte abnormalities, which can further impact kidney function and overall health. Choices B, C, and D are incorrect because increasing protein intake, limiting fluid intake, and encouraging a high-fat diet can exacerbate kidney disease in children by putting extra strain on their kidneys or causing other health problems.

4. How should one manage a child with an allergy to multiple food items?

A. Avoid all identified allergens
B. Increase dietary exposure to allergens
C. Administer daily antihistamines
D. Restrict all food intake

Correct answer: A

Rationale: When managing a child with an allergy to multiple food items, the most appropriate approach is to avoid all identified allergens. This is crucial to prevent allergic reactions and ensure the child's safety. Choice B, increasing dietary exposure to allergens, is incorrect as it can lead to severe allergic reactions. Choice C, administering daily antihistamines, may help manage symptoms but does not address the root cause, which is avoiding allergens. Choice D, restricting all food intake, is not a viable option as it can lead to malnutrition and other health issues.

5. Food energy is commonly expressed in kilocalories and in what other unit?

A. kilojoules
B. kilograms
C. kilometers
D. kilonewtons

Correct answer: A

Rationale: Food energy is commonly expressed in kilocalories and kilojoules. Kilocalories and kilojoules are both units of energy commonly used to measure the energy content of food. Kilograms, kilometers, and kilonewtons are units of mass, distance, and force, respectively, and are not used to express food energy.