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. Farah is viewing an exciting sports match of her favorite team and eating because of nervousness. Her food choice will most likely be based on ___.

A. regional cuisines
B. preferences
C. emotional comfort
D. positive association

Correct answer: C

Rationale: During stressful situations like watching an exciting sports match, individuals often seek emotional comfort through food. This emotional connection can lead Farah to choose foods that provide comfort or familiarity rather than being based on regional cuisines (choice A), general preferences (choice B), or positive associations (choice D). Farah's food choice is likely driven by the need for emotional comfort to alleviate her nervousness, making option C the most suitable answer.

3. What is the main function of proteins in the body?

A. They provide structural components for the body.
B. They assist in the absorption of vitamins.
C. They help with the transport of nutrients in the blood.
D. They help maintain fluid balance in the body.

Correct answer: A

Rationale: The main function of proteins in the body is to provide structural components like muscles, skin, and bones. Proteins are essential for growth, repair, and maintenance of body tissues. While proteins play a role in various physiological functions, their primary function is not to assist in the absorption of vitamins (Choice B), help with the transport of nutrients in the blood (Choice C), or maintain fluid balance (Choice D).

4. How should a healthcare provider address a child's concerns about a new medical diagnosis?

A. Provide clear and age-appropriate information
B. Avoid discussing the diagnosis
C. Refer to a specialist immediately
D. Suggest seeking alternative therapies

Correct answer: A

Rationale: Correct answer: Providing clear and age-appropriate information is crucial when addressing a child's concerns about a new medical diagnosis. Children often feel anxious and confused when faced with health issues, so offering them information in a way they can understand helps alleviate their fears and empowers them to cope better. Choice B is incorrect because avoiding discussing the diagnosis can lead to increased anxiety and uncertainty in the child. Choice C is incorrect as referring to a specialist immediately may not be necessary at the initial stage of addressing the child's concerns. Choice D is incorrect as suggesting alternative therapies without providing proper information about the medical diagnosis may not be suitable or effective.

5. In what position does the Pavlik harness hold a child's femurs for developmental hip dysplasia?

A. Abduction
B. Adduction
C. Flexion
D. Extension

Correct answer: A

Rationale: The Pavlik harness is designed to position a child's femurs in abduction for developmental hip dysplasia. Abduction helps align the hip joint correctly and promotes proper development in cases of hip dysplasia. Adduction (choice B) brings the legs closer to the midline, which is not the desired position in this condition. Flexion (choice C) refers to bending at a joint, while extension (choice D) is the opposite of flexion. However, in the case of developmental hip dysplasia, abduction is crucial for the Pavlik harness to work effectively.