Nursing Elites

1. What is the magnification of an ocular lens on a microscope?

• A. 4x
• B. 10x
• C. 40x
• D. 100x

Correct answer: B

Rationale: The magnification of an ocular lens on a microscope is typically 10x, which is considered standard for most microscopes. Ocular lenses are designed to magnify the image produced by the objective lens further. Choices A, C, and D are incorrect because they do not represent the standard magnification of an ocular lens. A magnification of 4x, 40x, or 100x would not be typical for an ocular lens in a microscope.

2. Which of the following is not true about enzymes?

• A. They catalyze reactions
• B. They lower the activation energy needed
• C. They have an active site
• D. They are typically proteins

Correct answer: B

Rationale: Enzymes lower the activation energy needed for a reaction to occur, not raise it. By lowering the activation energy, enzymes facilitate reactions, making them occur more easily and rapidly. Choice A is correct as enzymes indeed catalyze reactions. Choice C is correct as enzymes have specific active sites where substrates bind. Choice D is correct as enzymes are commonly proteins, although some RNA molecules also exhibit catalytic properties.

3. What happens during the S phase of the cell cycle?

• A. Chromosomes are duplicated.
• B. Cell growth occurs.
• C. DNA is synthesized.
• D. DNA is destroyed.

Correct answer: A

Rationale: During the S phase of the cell cycle, chromosomes are duplicated. This is a critical step in cell division as each chromosome is replicated to ensure that the resulting daughter cells receive an identical set of genetic information. Choices B, C, and D are incorrect because cell growth primarily occurs in the G1 phase, DNA synthesis happens during the S phase, and DNA destruction does not occur during any phase of the cell cycle.

4. Select the strand of DNA that would match this segment: ACTTGCA

• A. TGAACGT
• B. GACCATG
• C. ACTTGCA
• D. None of the above

Correct answer: A

Rationale: The correct match for the DNA segment ACTTGCA is TGAACGT. In DNA, adenine (A) always pairs with thymine (T), and cytosine (C) always pairs with guanine (G). Therefore, the complementary strand to ACTTGCA should be TGAACGT, making choice A the correct answer. Choice B (GACCATG) does not follow the base pairing rules; hence, it is incorrect. Choice C (ACTTGCA) is the original segment, not its complementary strand. Choice D is incorrect as well because a matching strand does exist.

5. What are the three types of muscle tissue?

• A. Cardiac, spinal, stomach
• B. Smooth, skeletal, cardiac
• C. Neuron, epithelial, collagen
• D. None of the above

Correct answer: B

Rationale: The correct answer is B: Smooth, skeletal, cardiac. Smooth muscle is found in organs like the stomach and is involuntarily controlled. Skeletal muscle is found in voluntary muscles, like the bicep or quadriceps. Cardiac muscle is found only in the heart walls and works involuntarily to make the heart beat and pump blood. Choices A, C, and D are incorrect because they do not represent the three types of muscle tissue.

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