Nursing Elites

1. What is the basic structural and functional unit of the nervous system?

• A. Axon
• B. Neuron
• C. Dendrite
• D. Synapse

Correct answer: B

Rationale: The correct answer is B: Neuron. Neurons are indeed the basic structural and functional units of the nervous system. Neurons are specialized cells that transmit signals throughout the nervous system, enabling communication and coordination of various functions within the body. While axons, dendrites, and synapses are all essential components of neurons and neural function, the neuron as a whole is considered the fundamental building block responsible for signal transmission. Choice A, Axon, is incorrect because an axon is a part of a neuron responsible for transmitting electrical signals away from the cell body. Choice C, Dendrite, is incorrect because dendrites are extensions of a neuron that receive signals from other neurons. Choice D, Synapse, is incorrect because a synapse is the junction between two neurons where signals are transmitted.

2. Which of the following scenarios represents an example of static friction?

• A. Sliding a heavy box across the floor
• B. A car moving around a curve
• C. Pushing a stationary object
• D. Braking a car to stop

Correct answer: C

Rationale: The correct answer is C. Static friction occurs when two surfaces are in contact but not moving relative to each other. Pushing a stationary object involves static friction as you apply a force to overcome the friction keeping the object stationary. Choices A, B, and D involve kinetic friction, which occurs when two surfaces are moving relative to each other. Option A involves moving the box across the floor, which is an example of kinetic friction. Option B involves the movement of a car around a curve, which also relates to kinetic friction due to the relative movement between the tires and the road. Option D describes braking a car to stop, where the moving car's wheels interact with the road, creating kinetic friction to slow down and stop the car.

3. Which of the following cations is found at the center of a heme?

• A. Cr (III)
• B. Cu (II)
• C. Iron (II)
• D. Iron (III)

Correct answer: C

Rationale: The correct answer is Iron (II) (Fe2+), which is the cation found at the center of a heme group. Heme contains an iron (II) ion that is coordinated within the porphyrin ring structure. This iron ion is crucial for the function of heme in binding and transporting oxygen in hemoglobin and myoglobin. Choice A (Cr (III)) is incorrect as chromium is not typically found at the center of a heme group. Choice B (Cu (II)) is incorrect as copper is not the cation typically present in heme. Choice D (Iron (III)) is also incorrect as heme predominantly contains iron (II) at its center, not iron (III).

4. In a covalent bond, the shared electrons:

• A. Are completely transferred to one atom.
• B. Spend more time closer to the more electronegative atom.
• C. Remain equidistant between the two atoms.
• D. Do not influence the bond strength.

Correct answer: B

Rationale: In a covalent bond, the shared electrons spend more time closer to the more electronegative atom. Electronegativity is the ability of an atom to attract electrons in a chemical bond. The more electronegative atom exerts a stronger pull on the shared electrons, causing them to be closer to that atom. Choice A is incorrect because in a covalent bond, electrons are shared, not completely transferred. Choice C is incorrect as the shared electrons are not equidistant but are closer to one atom due to electronegativity differences. Choice D is incorrect because shared electrons play a significant role in determining the bond strength by the strength of the bond formed through electron sharing.

5. Which of the following is part of the central nervous system?

• A. Spinal cord
• B. Peripheral nerves
• C. Brainstem
• D. Cerebellum

Correct answer: A

Rationale: The correct answer is A: Spinal cord. The central nervous system comprises the brain and spinal cord. The spinal cord plays a crucial role in transmitting information between the brain and the body. Choices B, C, and D are not part of the central nervous system. Peripheral nerves belong to the peripheral nervous system, whereas the brainstem and cerebellum are components of the brain, distinct from the central nervous system.

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