Nursing Elites

1. A person pushes a box across a floor with a constant force. The box eventually comes to a stop due to friction. What happens to the work done by the person?

• A. It increases as the box moves further.
• B. It decreases as the box slows down.
• C. It remains constant throughout the motion.
• D. It becomes zero once the box stops.

Correct answer: D

Rationale: Work done is defined as the product of the force applied and the distance moved in the direction of the force. In this scenario, when the box comes to a stop, the displacement becomes zero, leading to zero work done by the person. Choice A is incorrect as the work done is not increasing, but rather decreasing as the box slows down. Choice B is incorrect because the work done does not decrease as the box slows down; it becomes zero when the box stops. Choice C is incorrect as the work done is not constant but decreases to zero when the box stops.

2. Which hormone regulates the sleep-wake cycle?

• A. Cortisol
• B. Melatonin
• C. Thyroxine
• D. Insulin

Correct answer: B

Rationale: The correct answer is B: Melatonin. Melatonin, produced by the pineal gland, is the hormone that regulates the sleep-wake cycle. It helps signal to the body when it's time to sleep and wake up, playing a crucial role in maintaining a healthy sleep pattern. Choice A, Cortisol, is known as the stress hormone and plays a role in the body's response to stress, not specifically in regulating the sleep-wake cycle. Choice C, Thyroxine, is a hormone produced by the thyroid gland that regulates metabolism, not the sleep-wake cycle. Choice D, Insulin, is a hormone produced by the pancreas that regulates blood sugar levels, not the sleep-wake cycle.

3. How is power related to energy?

• A. Power is the same as energy
• B. Energy is the rate at which work is done
• C. Power is the amount of stored energy
• D. Energy is the rate at which power is transferred

Correct answer: B

Rationale: Energy is the capacity to do work, while power is the rate at which work is done or energy is transferred. Power is the amount of energy transferred or converted per unit time. Therefore, energy is related to power as the rate at which work is done. Choice A is incorrect because power and energy are not the same; they are related concepts but represent different aspects. Choice C is incorrect because power does not refer to stored energy but rather the rate of energy transfer. Choice D is incorrect because energy is not the rate at which power is transferred, but the capacity to do work or cause change.

4. Which structure in the respiratory system is responsible for voice production?

• A. Pharynx
• B. Larynx
• C. Trachea
• D. Bronchi

Correct answer: B

Rationale: The correct answer is the larynx. The larynx, commonly referred to as the voice box, is responsible for voice production in the respiratory system. It contains vocal cords that vibrate to produce sound. The pharynx is a passage for food and air, the trachea is a tubular structure that carries air to and from the lungs, and the bronchi are the main airway passages in the lungs. Therefore, choices A, C, and D are incorrect as they do not play a direct role in voice production.

5. Which of the following terms describes stem cells that have the ability to develop into any cell found in the human body?

• A. Totipotent stem cells
• B. Multipotent stem cells
• C. Pluripotent stem cells
• D. Hematopoietic stem cells

Correct answer: A

Rationale: Totipotent stem cells have the unique ability to differentiate into any cell type in the human body and can generate a complete organism. They are considered the most versatile type of stem cells, capable of developing into all cell types, including extraembryonic tissues. Choice A, Totipotent stem cells, is the correct answer as it specifically describes stem cells with the broadest differentiation potential. Choice B, Multipotent stem cells, refers to stem cells that can differentiate into a limited range of cell types. Choice C, Pluripotent stem cells, can give rise to almost all cell types, but not the complete organism like totipotent stem cells. Choice D, Hematopoietic stem cells, are a type of multipotent stem cells that give rise to various blood cell types, but do not have the same broad differentiation potential as totipotent stem cells.

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