which vitamin is essential for maintaining healthy skin and vision

HESI A2

Anatomy and Physiology Hesi A2 Practice Test

1. Which vitamin is essential for maintaining healthy skin and vision?

A. Vitamin C
B. Vitamin A
C. Vitamin D
D. Vitamin K

Correct answer: B

Rationale: Vitamin A is the correct answer. It is essential for maintaining healthy skin and vision, especially in low-light conditions. Vitamin A helps in the production of retinal pigments necessary for vision in dim light and supports skin health by promoting cell turnover and repair. Choice A, Vitamin C, is important for the immune system and collagen production but is not specifically known for maintaining skin and vision health. Choice C, Vitamin D, is crucial for bone health and immune function but is not directly related to skin and vision health. Choice D, Vitamin K, is necessary for blood clotting and bone health but does not play a significant role in maintaining healthy skin and vision.

2. How should a researcher test the hypothesis that eating chocolate leads to acne in teenagers?

A. Take 100 teenagers and feed each one a different amount of chocolate daily for 60 days; then test for acne.
B. Take 100 teenagers and feed 50 two bars of chocolate daily for 60 days while the other 50 eat no chocolate; then test for acne.
C. Take 1 teenager and feed him or her two bars of chocolate for 30 days and no chocolate for 30 days; then test for acne.
D. Take 100 teenagers and feed them no chocolate for 30 days and two bars of chocolate apiece for 30 days; then test for acne.

Correct answer: B

Rationale: Option B is the correct approach to test the hypothesis that eating chocolate leads to acne in teenagers. This method involves having a control group (50 teenagers not consuming chocolate) and an experimental group (50 teenagers consuming two bars of chocolate daily), which allows for comparison. By having two distinct groups, researchers can assess the impact of chocolate consumption on acne development. Option A lacks a control group for comparison, making it harder to attribute any observed effects specifically to chocolate consumption. Option C only involves a single subject, which limits the generalizability of the results. Option D, where all teenagers experience both conditions, does not allow for a direct comparison between chocolate consumption and acne development, as all subjects are exposed to both conditions.

3. What is the main idea of the passage about Sunny-Side Up?

A. There are many positive effects of receiving direct exposure to sunlight.
B. The negative impacts of sunlight should not be ignored.
C. Vitamin D is integral for maintaining healthy bones and preventing diseases.
D. Vitamin D is synthesized by our bodies in reaction to direct sunlight.

Correct answer: A

Rationale: The passage primarily discusses the various positive effects of sunlight exposure, particularly highlighting the benefits of vitamin D for bone health and the regulation of circadian rhythms. While it acknowledges the negative impacts of excessive sun exposure, the emphasis is on the positive aspects, making A the main idea of the passage.

4. Aluminum (Al) has 13 protons in its nucleus. What is the number of electrons in an Al3+ ion?

A. 16
B. 13
C. 10
D. 3

Correct answer: C

Rationale: Aluminum (Al) has an atomic number of 13, which indicates it normally has 13 electrons to balance the 13 protons in its nucleus. When Al forms an Al3+ ion, it loses 3 electrons to achieve a stable electron configuration. Therefore, the Al3+ ion will have 13 - 3 = 10 electrons. Choice A (16) is incorrect as it doesn't take into account the charge of the Al3+ ion. Choice B (13) is incorrect because the Al3+ ion has lost electrons. Choice D (3) is incorrect as it doesn't reflect the total number of electrons lost by the Al atom to form the Al3+ ion.

5. If a package of 10 pencils is divided between every 2 students in a class with 20 students, how many pencils are needed?

A. 20
B. 40
C. 80
D. 100

Correct answer: D

Rationale: If 20 students are divided into pairs, there would be 10 pairs in total (20 students / 2 = 10 pairs). Since each pair receives 10 pencils, the total number of pencils needed is calculated by multiplying the number of pairs (10 pairs) by the number of pencils each pair receives (10 pencils per pair), resulting in 100 pencils required. Therefore, the correct answer is 100 pencils. Choices A, B, and C are incorrect because they do not consider the correct pairing of students or the total number of pencils needed for each pair.