Nursing Elites

1. Which element is used in fluorescent lamps and emits ultraviolet light when excited?

• A. Mercury
• B. Neon
• C. Argon
• D. Krypton

Correct answer: A

Rationale: Mercury is the correct element used in fluorescent lamps to emit ultraviolet light when excited. When an electric current passes through the mercury vapor inside the lamp, it generates ultraviolet (UV) light. This UV light then excites the phosphors coated on the inner surface of the lamp, causing them to emit visible light. Neon, argon, and krypton are not commonly used in fluorescent lamps for this purpose. Neon is primarily used in neon signs, argon is used in incandescent and fluorescent bulbs for inertia gas, and krypton is mainly used in certain types of specialized light bulbs for its specific properties.

2. Which of the following accurately describes saltatory conduction?

• A. It is faster than normal nerve conduction
• B. It occurs from one node of Ranvier to the next
• C. It only occurs in myelinated neurons
• D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Saltatory conduction is faster than normal nerve conduction, occurs from one node of Ranvier to the next, and is exclusive to myelinated neurons. This form of conduction allows for the rapid transmission of nerve impulses by the action potential jumping between the nodes of Ranvier in myelinated neurons, enhancing the efficiency of signal propagation along the axon. Choice A is correct as saltatory conduction is indeed faster than normal conduction. Choice B is accurate as it describes the mechanism of conduction 'jumping' from one node of Ranvier to the next. Choice C is correct because saltatory conduction occurs specifically in myelinated neurons where the myelin sheath insulates the axon except at the nodes of Ranvier, facilitating faster transmission of nerve impulses.

3. From which of the following germ layers does the nervous system develop?

• A. Ectoderm
• B. Endoderm
• C. Gastroderm
• D. Mesoderm

Correct answer: A

Rationale: The correct answer is A: Ectoderm. The nervous system develops from the ectoderm, which is the outermost of the three germ layers. The ectoderm gives rise to structures such as the skin, hair, nails, and the entire nervous system. Choices B, C, and D are incorrect because the endoderm gives rise to the lining of the gut and associated organs, the gastroderm is not a recognized germ layer, and the mesoderm forms structures like muscles, bones, blood, and the circulatory system, but not the nervous system.

4. During a scientific investigation, what is intentionally changed or manipulated?

• A. The dependent variable.
• B. The control.
• C. The hypothesis.
• D. The independent variable.

Correct answer: D

Rationale: During a scientific investigation, the independent variable is intentionally changed or manipulated by the researcher to observe its impact or effect on the dependent variable. The independent variable is the one being tested or studied to see how it influences the dependent variable. In contrast, the dependent variable is the outcome or response that is measured in an experiment and is expected to change as a result of the manipulation of the independent variable. Choices A, B, and C are not directly altered during a scientific investigation but play different roles in the research process. Therefore, the correct answer is D - the independent variable.

5. What is a characteristic property of acids?

• A. Bitter taste
• B. Sour taste
• C. Slippery feel
• D. Sweet taste

Correct answer: B

Rationale: The correct characteristic property of acids is a sour taste. Acids release hydrogen ions when dissolved in water, giving them a sour taste. Bitter taste is a property associated with bases, not acids. Slippery feel is a characteristic property of bases, due to their soap-like nature. Sweet taste does not accurately describe the characteristic property of acids, as they are known for their sour taste.

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