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. How should a caregiver manage a child with a known allergy to peanuts?

A. Avoid all peanut-containing products
B. Encourage regular exposure to peanuts
C. Administer antihistamines daily
D. Recommend peanut-containing supplements

Correct answer: A

Rationale: Avoiding peanut-containing products is crucial for managing a peanut allergy and preventing allergic reactions. Choice B suggesting regular exposure to peanuts can be harmful and trigger severe allergic reactions in a child with a peanut allergy. Regular exposure can increase the risk of anaphylaxis. Choice C of administering antihistamines daily is not a primary prevention strategy and should not be the first-line approach for managing a peanut allergy. Antihistamines only treat symptoms and do not prevent the allergic reaction. Choice D of recommending peanut-containing supplements can also lead to severe allergic reactions and is not recommended for a child with a known peanut allergy. It is essential to eliminate all sources of peanuts to prevent accidental exposure and potential life-threatening reactions.

3. How many minerals are known to be essential for human nutrition?

A. 8
B. 12
C. 16
D. 20

Correct answer: C

Rationale: There are 16 essential minerals required for human nutrition. These minerals include calcium, potassium, iron, and others. Choice A (8) is incorrect as it underestimates the number of essential minerals. Choice B (12) is also incorrect as it does not encompass the full count of essential minerals. Choice D (20) is incorrect as it overestimates the number of essential minerals.

4. How should a caregiver manage a child with a newly diagnosed hearing impairment?

A. Increase the volume of all auditory stimuli
B. Refer for audiologic evaluation and intervention
C. Avoid using any assistive devices
D. Encourage frequent use of headphones

Correct answer: B

Rationale: When a child is newly diagnosed with a hearing impairment, it is essential to refer them for audiologic evaluation and intervention. This step is crucial to accurately assess the extent of the impairment, determine appropriate interventions, and support the child's communication and development. Increasing the volume of all auditory stimuli (choice A) is not a recommended approach as it may not address the specific needs of the child and could potentially cause discomfort. Avoiding the use of assistive devices (choice C) can hinder the child's ability to communicate effectively. Encouraging frequent use of headphones (choice D) is also not advisable as it may not be suitable for managing hearing impairments and could potentially worsen the condition.

5. Which statement is true of minerals in their role as nutrients?

A. They are organic compounds.
B. They yield 4 kilocalories per gram.
C. Some become dissolved in body fluids.
D. Some are destroyed during cooking.

Correct answer: C

Rationale: The correct statement is that some minerals become dissolved in body fluids, making them available for absorption and utilization by the body. Minerals are not organic compounds, so choice A is incorrect. Choice B is incorrect because minerals do not provide energy like macronutrients such as carbohydrates and fats. Choice D is incorrect because minerals are elements and cannot be destroyed by cooking; however, their availability and absorption may be affected by cooking methods.