Nursing Elites

1. Which types of waves are capable of interference and diffraction?

• A. Longitudinal waves only
• B. Transverse waves only
• C. Electromagnetic waves only
• D. Both longitudinal and transverse waves

Correct answer: D

Rationale: Both longitudinal and transverse waves are capable of interference and diffraction. Interference occurs when two or more waves overlap and combine, either constructively (increasing amplitude) or destructively (decreasing amplitude). Diffraction is the bending of waves around obstacles or through openings, which can occur with both longitudinal and transverse waves. Choice A is incorrect because only stating longitudinal waves can undergo interference and diffraction is inaccurate. Choice B is also incorrect as transverse waves, not just longitudinal waves, can exhibit these phenomena. Choice C is incorrect because electromagnetic waves are a broad category that includes both longitudinal and transverse waves, so it is not exclusive to either type. The correct answer is D because both longitudinal and transverse waves can demonstrate interference and diffraction.

2. Which hormone stimulates the release of calcium from bones and increases blood calcium levels?

• A. Parathyroid hormone (PTH)
• B. Calcitonin
• C. Growth hormone
• D. Testosterone

Correct answer: A

Rationale: Parathyroid hormone (PTH) is the correct answer. PTH stimulates the release of calcium from bones, leading to increased blood calcium levels. It acts on the bones to release calcium into the bloodstream, facilitates the kidneys' reabsorption of calcium, and triggers vitamin D activation to boost calcium absorption from the intestines. Choice B, Calcitonin, is incorrect as it works in opposition to PTH by decreasing blood calcium levels through inhibiting calcium release from bones. Choices C and D, Growth hormone and Testosterone, are not directly involved in calcium homeostasis and do not regulate blood calcium levels through bone calcium release mechanisms.

3. Which of the following structures is responsible for transmitting electrical impulses in the nervous system?

• A. Neuron
• B. Axon
• C. Myelin
• D. Dendrite

Correct answer: A

Rationale: The correct answer is A: Neuron. Neurons are specialized cells that transmit electrical impulses in the nervous system. While the axon is the part responsible for conducting these impulses over long distances, it is the neuron as a whole that is ultimately responsible for transmitting electrical impulses. Myelin is a fatty substance that surrounds and insulates axons, speeding up signal transmission. Dendrites, on the other hand, receive signals from other neurons. Therefore, although the axon plays a significant role in transmission, the neuron is the fundamental unit responsible for transmitting electrical impulses in the nervous system.

4. What is the final phase of mitosis?

• A. Prophase
• B. Telophase
• C. Anaphase
• D. Metaphase

Correct answer: B

Rationale: Telophase is indeed the final phase of mitosis. During telophase, the chromosomes have reached opposite poles of the cell, the nuclear envelope is re-forming around the separated sister chromatids, and cytokinesis may also occur, leading to the division of the cell into two daughter cells. Choice A, Prophase, is incorrect as it is the initial phase of mitosis where chromatin condenses into chromosomes. Choice C, Anaphase, is incorrect as it is the phase where sister chromatids separate and move towards opposite poles. Choice D, Metaphase, is incorrect as it is the phase where chromosomes align at the cell's equator before separating.

5. In the context of cholesterol levels, LDL cholesterol is often referred to as:

• A. HDL or "good" cholesterol.
• B. LDL or "bad" cholesterol.
• C. Total cholesterol, encompassing both LDL and HDL.
• D. VLDL, a type of triglyceride transported in the bloodstream.

Correct answer: B

Rationale: LDL cholesterol is often referred to as "bad" cholesterol because high levels of LDL can lead to plaque buildup in the arteries, increasing the risk of heart disease and stroke. LDL cholesterol is considered harmful as it contributes to the formation of plaque in blood vessels, whereas HDL cholesterol helps remove LDL from the arteries. Choice A is incorrect because HDL is known as "good" cholesterol, which helps remove LDL cholesterol from the bloodstream. Choice C is incorrect as it refers to total cholesterol, which includes LDL, HDL, and other lipids. Choice D is incorrect as VLDL is a different type of lipoprotein that carries triglycerides and is not specifically related to LDL cholesterol.

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