Nursing Elites

1. How do isotopes affect the atomic mass of an element?

• A. Isotopes have no effect on the atomic mass of an element.
• B. Isotopes cause the atomic mass of an element to vary slightly.
• C. Isotopes cause the atomic mass of an element to be exactly the same for all isotopes of that element.
• D. Isotopes cause the atomic mass of an element to vary greatly.

Correct answer: B

Rationale: Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Since the atomic mass of an element is the weighted average of the masses of its isotopes, the presence of isotopes causes the atomic mass of an element to vary slightly. This variation occurs because different isotopes have different masses due to their varying numbers of neutrons. The atomic mass is affected by the abundance of each isotope, leading to a slight fluctuation in the overall atomic mass of the element. Choice A is incorrect because isotopes do influence the atomic mass. Choice C is incorrect because isotopes have different masses, affecting the overall atomic mass. Choice D is incorrect as isotopes typically do not cause a significant variation in atomic mass, but rather a slight fluctuation.

2. Which of the following terms refers to a muscle twitch, a single forceful contraction of a muscle fiber?

• A. Tetanus
• B. Tremor
• C. Fasciculation
• D. Rigidity

Correct answer: C

Rationale: The correct term for a muscle twitch, a single forceful contraction of a muscle fiber, is 'Fasciculation' (choice C). Fasciculation specifically describes this phenomenon. 'Tetanus' (choice A) refers to sustained muscle contraction, 'Tremor' (choice B) indicates a shaky or quivering movement, and 'Rigidity' (choice D) denotes stiffness or inflexibility in muscles. Therefore, choices A, B, and D are incorrect in the context of a single forceful contraction of a muscle fiber.

3. What is surgically altered during a vasectomy?

• A. Vas deferens
• B. Glans penis
• C. Prostate
• D. Urethra

Correct answer: A

Rationale: During a vasectomy, the vas deferens is surgically altered or cut to prevent the transport of sperm from the testicles to the urethra. This procedure is a form of permanent male sterilization. The glans penis, prostate, and urethra are not surgically altered during a vasectomy. Therefore, the correct answer is the vas deferens (Choice A), as it is the structure specifically targeted and modified in this procedure. The glans penis (Choice B) is the sensitive tip of the penis, the prostate (Choice C) is a gland vital for semen production but not involved in a vasectomy, and the urethra (Choice D) is the tube that carries urine and semen but is not surgically altered in a vasectomy.

4. What is involved in the involuntary reflex arc that withdraws your hand from a hot object?

• A. Central nervous system only
• B. Peripheral nervous system only
• C. Both CNS and PNS
• D. Sensory neurons only

Correct answer: C

Rationale: The involuntary reflex arc that withdraws your hand from a hot object involves both the central nervous system (CNS) and the peripheral nervous system (PNS). When your hand touches a hot object, sensory neurons in the PNS detect the heat and send signals to the spinal cord in the CNS. The spinal cord processes this information and sends a signal back through motor neurons in the PNS to move your hand away from the hot object. This coordinated response requires the collaboration of both the CNS and PNS to protect the body from harm. Choice A is incorrect because the reflex arc involves more than just the central nervous system. Choice B is incorrect because the reflex arc involves more than just the peripheral nervous system. Choice D is incorrect because the reflex arc also involves motor neurons, not just sensory neurons.

5. What is the definition of 'acceleration' in terms of motion?

• A. Change in velocity over time
• B. Speed in a straight line
• C. Distance covered in a given time
• D. Force applied to an object

Correct answer: A

Rationale: Acceleration is defined as the rate of change of velocity of an object over time. It represents how an object's velocity is changing, either by speeding up, slowing down, or changing direction. Option B, 'Speed in a straight line,' actually refers to velocity, not acceleration. Option C, 'Distance covered in a given time,' is more related to speed, as it measures how much ground is covered in a specific time period. Option D, 'Force applied to an object,' is not the definition of acceleration; it is a force exerted on an object that can cause acceleration.

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