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 one primary factor that influences nutrient needs in individuals?

A. Age
B. Gender
C. Genetics
D. Physical activity level

Correct answer: A

Rationale: Correct. Age is one of the primary factors influencing nutrient needs. Different life stages, such as infancy, childhood, adulthood, and old age, require varying amounts of nutrients. Gender (choice B) can influence nutrient needs to some extent, but age plays a more significant role. Genetics (choice C) may affect how individuals metabolize certain nutrients but is not a primary factor in determining overall nutrient needs. Physical activity level (choice D) can impact energy requirements but is not as fundamental as age in influencing overall nutrient needs.

3. What does the term 'essential nutrient' refer to?

A. A nutrient that can be synthesized by the body.
B. A nutrient that is required for proper body functioning.
C. A nutrient that must be obtained from the diet because the body cannot produce it.
D. A nutrient that can be stored in the body for long periods.

Correct answer: C

Rationale: The correct answer is C. An essential nutrient is a substance that is necessary for normal body functioning but cannot be synthesized in adequate amounts by the body, therefore it must be obtained from the diet. Choices A, B, and D are incorrect because essential nutrients are not synthesized by the body, they are necessary for body functioning, and they are not typically stored in the body for long periods.

4. How should a healthcare professional manage a child with a newly inserted central venous catheter?

A. Monitor for signs of infection
B. Restrict all physical activity
C. Administer routine antibiotics
D. Increase fluid intake only

Correct answer: A

Rationale: Monitoring for signs of infection is crucial in managing a central venous catheter to prevent complications. This involves observing for redness, swelling, warmth, or drainage at the catheter site, as these can indicate an infection. Restricting physical activity unnecessarily (choice B) can hinder the child's recovery and quality of life. Administering routine antibiotics (choice C) without a confirmed infection can lead to antibiotic resistance and unnecessary side effects. Increasing fluid intake only (choice D) is not the primary intervention for managing a central venous catheter.

5. The motive for a person who alters their diet due to religious convictions is most likely related to their ___.

A. values
B. body image
C. ethnic heritage
D. functional association

Correct answer: A

Rationale: The correct answer is A, 'values.' When individuals alter their diet due to religious convictions, it is primarily driven by their personal or cultural values associated with their faith. This choice reflects the strong influence that religious beliefs can have on dietary choices. Choice B, 'body image,' is incorrect because altering one's diet for religious reasons is more about spiritual beliefs than physical appearance. Choice C, 'ethnic heritage,' is incorrect as it pertains more to cultural background rather than religious convictions. Choice D, 'functional association,' is incorrect as it does not directly relate to the motivation behind altering one's diet for religious reasons.