Nursing Elites

1. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

• A. Schwann cells
• B. Astrocytes
• C. Neurons
• D. Oligodendrocytes

Correct answer: A

Rationale: The correct answer is A: Schwann cells. Schwann cells are a type of glial cell in the peripheral nervous system that produce the myelin sheath around axons. Myelin sheath is essential for the rapid conduction of nerve impulses and provides insulation and protection to nerve fibers. Astrocytes are glial cells that provide support and maintain homeostasis in the central nervous system, but they do not produce myelin. Neurons are the main functional units of the nervous system responsible for transmitting nerve impulses. Oligodendrocytes are another type of glial cell in the central nervous system that produce myelin sheath around axons in that region, not in the peripheral nervous system where Schwann cells are responsible for myelination.

2. 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 related to the amount of work done or the capacity to do work, while power measures the rate at which work is done or energy is transferred.

3. The doctor carefully examined the patient. Which word is the comparative form of the adjective "careful"?

• A. careful
• B. carelessly
• C. more careful
• D. most careful

Correct answer: C

Rationale: The comparative form of an adjective compares two things.

4. Which sentence avoids a comma splice?

• A. The wind howled, the branches swayed, and rain lashed against the windows.
• B. He packed his bags, he checked the weather forecast, and then hit the road.
• C. The movie was entertaining, it was also thought-provoking.
• D. Tired and hungry, she stopped for a quick bite at the cafe.

Correct answer: C

Rationale: Option C uses a semicolon to separate two independent clauses, avoiding a comma splice.

5. Which of the following describes the difference between prokaryotic and eukaryotic cells?

• A. Prokaryotic cells have a nucleus, while eukaryotic cells don't.
• B. Eukaryotic cells are simpler in structure than prokaryotic cells.
• C. Prokaryotic cells have membrane-bound organelles, while eukaryotic cells don't.
• D. Eukaryotic cells have a true nucleus and membrane-bound organelles, while prokaryotic cells lack these.

Correct answer: A

Rationale: The correct answer is A: 'Prokaryotic cells have a nucleus, while eukaryotic cells don't.' Prokaryotic cells lack a membrane-bound nucleus and other membrane-bound organelles, while eukaryotic cells have a true nucleus enclosed within a nuclear membrane. This distinction is a fundamental difference between the two cell types. Choice B is incorrect because eukaryotic cells are actually more complex than prokaryotic cells due to their membrane-bound organelles. Choice C is incorrect because prokaryotic cells lack membrane-bound organelles. Choice D is incorrect because eukaryotic cells have both a true nucleus and membrane-bound organelles, unlike prokaryotic cells. Understanding this key difference is crucial in understanding the diversity of cell types in living organisms.

6. Which property of a substance refers to its ability to undergo a chemical change and form new substances?

• A. Density
• B. Mass
• C. Reactivity
• D. Volume

Correct answer: c

Rationale: Reactivity refers to a substance's ability to undergo chemical changes, forming new substances with different properties.

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