Nursing Elites

1. The resolution of an optical instrument, like a microscope, refers to its ability to distinguish between:

• A. Different colors of light
• B. The presence or absence of light
• C. Variations in intensity
• D. Very close, nearly identical objects

Correct answer: D

Rationale: The resolution of an optical instrument, such as a microscope, refers to its ability to distinguish between very close, nearly identical objects. This is crucial in microscopy to clearly visualize and differentiate fine details and structures. Resolving power plays a significant role in determining the quality and effectiveness of an optical instrument. Choices A, B, and C are incorrect because the resolution of an optical instrument does not primarily deal with different colors of light, presence or absence of light, or variations in intensity. Instead, it specifically focuses on the instrument's ability to differentiate between objects that are very close and nearly identical in nature.

2. During which phase of the cardiac cycle do the atria contract, pushing blood into the ventricles?

• A. Atrial diastole
• B. Ventricular systole
• C. Atrial systole
• D. Ventricular diastole

Correct answer: C

Rationale: Atrial systole is the phase of the cardiac cycle during which the atria contract, pushing blood into the ventricles. This occurs after the atria have been filled during atrial diastole. Ventricular systole refers to the phase when the ventricles contract to push blood out of the heart, not when the atria contract. Ventricular diastole is the phase when the ventricles relax and fill with blood, not when the atria contract. Therefore, the correct answer is atrial systole as it specifically describes the atrial contraction phase.

3. What term describes the bending of waves around obstacles or through openings?

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Absorption

Correct answer: C

Rationale: The correct answer is C, Diffraction. Diffraction is the phenomenon that explains the bending of waves around obstacles or through openings. When waves encounter obstacles or pass through openings, they spread out and bend around them. Reflection (Choice A) involves waves bouncing back when they encounter a surface without bending, refraction (Choice B) is the bending of waves when passing from one medium to another due to a change in speed, and absorption (Choice D) is the process of a wave being taken in by a material rather than bending or bouncing.

4. At the peak of its trajectory, what force is acting on a ball thrown upwards?

• A. Gravity only
• B. Gravity and air resistance only
• C. Neither gravity nor air resistance
• D. All of the above

Correct answer: A

Rationale: At the peak of its trajectory, the ball momentarily stops moving upwards before it starts to fall back down. At this point, the only force acting on the ball is gravity, pulling it back towards the ground. Air resistance is negligible at the peak of the trajectory as the ball is momentarily stationary. Therefore, the correct answer is 'Gravity only.' Choices B, C, and D are incorrect. Option B is incorrect because air resistance is minimal when the ball is at its highest point and its velocity is nearly zero. Option C is incorrect as gravity is the only significant force acting on the ball at that instant. Option D is incorrect since air resistance is not a significant factor at the peak of the trajectory.

5. How does RNA polymerase differ from DNA polymerase?

• A. Both enzymes are identical in function and structure.
• B. RNA polymerase does not require a primer to initiate RNA synthesis.
• C. RNA polymerase can synthesize both RNA and DNA.
• D. RNA polymerase can only synthesize RNA, unlike DNA polymerase.

Correct answer: B

Rationale: Rationale: A) This statement is incorrect. RNA polymerase and DNA polymerase are not identical in function and structure. They have different roles in the cell. B) This statement is correct. Unlike DNA polymerase, RNA polymerase does not require a primer to initiate RNA synthesis. RNA polymerase can start the synthesis of RNA de novo. C) This statement is incorrect. RNA polymerase is specialized for synthesizing RNA, not DNA. DNA polymerase is responsible for synthesizing DNA. D) This statement is correct. RNA polymerase can only synthesize RNA, while DNA polymerase is responsible for synthesizing DNA.

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