Nursing Elites

1. What is the function of the myelin sheath in a neuron?

• A. To transmit electrical impulses
• B. To insulate and speed up electrical signals
• C. To produce neurotransmitters
• D. To protect the neuron from damage

Correct answer: B

Rationale: The myelin sheath serves to insulate neurons and accelerate the transmission of electrical signals along the axon. This insulation helps in the efficient conduction of nerve impulses by preventing signal loss or leakage. Choice A is incorrect because the myelin sheath does not transmit electrical impulses itself but rather helps in the conduction. Choice C is incorrect as the myelin sheath is not responsible for producing neurotransmitters. Choice D is also incorrect as the primary function of the myelin sheath is not to protect the neuron from damage. Therefore, the correct answer is B, as it accurately describes the function of the myelin sheath in a neuron.

2. What is the process of making copies of RNA from DNA called?

• A. Replication
• B. Transcription
• C. Translation
• D. DNA repair

Correct answer: B

Rationale: Transcription is the correct answer. Transcription is the process of making copies of RNA from DNA. During transcription, the enzyme RNA polymerase binds to a specific region of DNA and synthesizes a complementary RNA strand based on the DNA template. This process is essential for gene expression and protein synthesis in cells. Replication (option A) refers to the process of making copies of DNA, not RNA. Translation (option C) is the process of synthesizing proteins from mRNA, not making copies of RNA from DNA. DNA repair (option D) involves mechanisms that cells use to repair damaged DNA, not the process of making RNA copies from DNA.

3. Which of the following is an example of a polymer?

• A. Methane
• B. Ethanol
• C. Polyethylene
• D. Acetic acid

Correct answer: C

Rationale: The correct answer is C, Polyethylene. Polyethylene is a polymer composed of a large number of repeating ethylene units linked together, forming a long-chain molecule, characteristic of polymers. Methane, ethanol, and acetic acid are small organic molecules that do not demonstrate the repeating unit structure typical of polymers. Therefore, they are not examples of polymers.

4. What is the principle behind the phenomenon of refraction, where waves bend when entering a new medium?

• A. Change in wavelength
• B. Change in frequency
• C. Change in wave speed
• D. None of the above

Correct answer: C

Rationale: Refraction occurs due to a change in wave speed when waves enter a new medium. As waves travel from one medium to another, their speed changes, causing them to bend. This change in speed is responsible for the bending of waves during refraction. It is not the change in wavelength or frequency that causes refraction, but rather the change in speed as waves move through different mediums. Therefore, the correct answer is the change in wave speed (Choice C). Choices A and B are incorrect as refraction is not primarily influenced by changes in wavelength or frequency, but by changes in wave speed. Choice D is also incorrect as there is a specific principle, which is the change in wave speed, behind the phenomenon of refraction.

5. What element has the atomic number 17?

• A. Chlorine (Cl)
• B. Nitrogen (N)
• C. Sodium (Na)
• D. Fluorine (F)

Correct answer: A

Rationale: The correct answer is Chlorine (Cl). The atomic number of an element corresponds to the number of protons in its nucleus. Chlorine has an atomic number of 17, indicating it has 17 protons. Therefore, the element with atomic number 17 is Chlorine (Cl). Choice B, Nitrogen (N), has an atomic number of 7, Choice C, Sodium (Na), has an atomic number of 11, and Choice D, Fluorine (F), has an atomic number of 9. These elements do not match the atomic number 17, making them incorrect choices.

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