Nursing Elites

1. What is the function of a cell wall?

• A. To provide structural support for the cell
• B. To transport substances in and out of the cell
• C. To synthesize proteins and lipids
• D. To store genetic material

Correct answer: A

Rationale: The cell wall is a rigid layer that surrounds the cell membrane in plant cells, fungi, and some bacteria. Its main function is to provide structural support and protection for the cell, helping maintain the cell's shape and preventing it from bursting or collapsing. The cell wall also allows for the passage of water, ions, and other molecules in and out of the cell. Options B, C, and D are incorrect because those functions are typically carried out by other cellular structures. Option B is performed by the cell membrane, option C by ribosomes, and option D by the nucleus, which stores genetic material.

2. Which of the following can weaken the immune system and increase susceptibility to infections?

• A. Regular exercise
• B. Balanced diet
• C. Chronic stress
• D. Adequate sleep

Correct answer: C

Rationale: Chronic stress can weaken the immune system by increasing the production of stress hormones like cortisol, which can suppress the immune response. This suppression can make individuals more susceptible to infections and illnesses. Conversely, regular exercise, a balanced diet, and adequate sleep actually support a healthy immune system and help strengthen it. Choices A, B, and D are incorrect as they are factors that generally contribute positively to the immune system. Regular exercise, a balanced diet, and adequate sleep are crucial for maintaining overall health and boosting the immune system rather than weakening it.

3. Scoliosis is a condition characterized by abnormal lateral curvature of the spine. Which part of the spine is most commonly affected?

• A. Cervical spine (neck)
• B. Thoracic spine (upper back)
• C. Lumbar spine (lower back)
• D. All of the above

Correct answer: B

Rationale: Scoliosis most commonly affects the thoracic spine, which is the upper back region. While scoliosis can potentially affect any part of the spine, the thoracic spine is the most frequently involved area. This region is more commonly affected due to the natural structural curves of the spine and the biomechanics of the thoracic area. The cervical spine (neck) and lumbar spine (lower back) can also be affected by scoliosis, but the thoracic spine is the primary area of involvement in most cases. Therefore, the correct answer is B, as it is the part of the spine most commonly affected by scoliosis.

4. The critical angle is defined as the minimum angle of incidence in a denser medium for which light undergoes:

• A. Total internal reflection
• B. Continued refraction
• C. Specular reflection
• D. Increased dispersion

Correct answer: A

Rationale: The critical angle is the minimum angle of incidence in a denser medium at which light undergoes total internal reflection instead of refraction. This phenomenon occurs when light travels from a denser medium to a less dense medium, and the angle of incidence is greater than the critical angle. Total internal reflection is a crucial concept in optics and is utilized in various applications such as fiber optics and prisms. Choice B, 'Continued refraction,' is incorrect as the critical angle specifically marks the point at which total internal reflection occurs, not continued refraction. Choice C, 'Specular reflection,' does not accurately describe the phenomenon associated with the critical angle. Choice D, 'Increased dispersion,' is unrelated to the concept of the critical angle and does not describe the behavior of light at this specific point.

5. What happens to the speed of a sound wave when it travels from air to water?

• A. It increases because water is denser.
• B. It decreases because water is denser.
• C. It remains the same.
• D. Speed depends on the frequency, not the medium.

Correct answer: B

Rationale: When a sound wave travels from air to water, the speed of sound decreases because sound travels faster in denser mediums. Water, being denser than air, causes the speed of sound to slow down. Choice A is incorrect because sound travels faster in denser mediums, so the speed would not increase. Choice C is incorrect because the speed of sound changes when transitioning between different mediums. Choice D is incorrect because while frequency does affect sound, the medium it travels through also plays a significant role in determining the speed of sound.

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