Nursing Elites

1. Which of the following describes a reflex arc?

• A. The storage and recall of memory
• B. The maintenance of visual and auditory acuity
• C. The autoregulation of heart rate and blood pressure
• D. A stimulus and response controlled by the spinal cord

Correct answer: D

Rationale: Choice D correctly describes a reflex arc. A reflex arc is a neural pathway that controls a reflex action. It involves a specific sequence of events that occur in response to a stimulus, which is rapidly and involuntarily processed by the spinal cord. The spinal cord coordinates the quick processing of sensory input and the generation of a motor response without involving the brain, allowing for rapid protective responses. Choices A, B, and C are incorrect because they do not accurately describe a reflex arc. A reflex arc is specifically related to the rapid and involuntary response to a stimulus through neural pathways involving the spinal cord, not memory storage, visual and auditory acuity maintenance, or heart rate and blood pressure autoregulation.

2. Which of the following functions would be most affected by laryngeal damage?

• A. Blinking
• B. Walking
• C. Singing
• D. Hearing

Correct answer: C

Rationale: Laryngeal damage would most affect the function of singing. The larynx, or voice box, houses the vocal cords responsible for producing sound during singing. Damage to the larynx can impair the ability to phonate and control pitch, tone, and quality of the voice, which are crucial for singing. Choices A, B, and D are unrelated to the larynx. Blinking is controlled by the facial nerve, walking involves motor functions and coordination, and hearing is related to the ear structures and auditory nerves.

3. What are the differences between RNA and DNA?

• A. Both have the same structure and function.
• B. RNA is single-stranded, while DNA is double-stranded.
• C. RNA contains ribose sugar, while DNA contains deoxyribose sugar.
• D. RNA has adenine and guanine, while DNA has thymine and cytosine.

Correct answer: B

Rationale: A) This statement is incorrect. RNA and DNA have different structures and functions. RNA is involved in protein synthesis and other cellular processes, while DNA stores genetic information. B) This statement is correct. RNA is typically single-stranded, while DNA is double-stranded, forming a double helix structure. C) This statement is correct. RNA contains ribose sugar in its backbone, while DNA contains deoxyribose sugar. D) This statement is incorrect. RNA contains adenine, guanine, cytosine, and uracil, while DNA contains adenine, guanine, cytosine, and thymine. Choice B is the correct answer as it accurately describes one of the key differences between RNA and DNA, emphasizing their structural disparity in terms of single-strandedness for RNA and double-strandedness for DNA. Choices A, C, and D contain inaccuracies regarding the structural and compositional distinctions between RNA and DNA, making them incorrect choices.

4. Which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow?

• A. Skeletal muscle
• B. Smooth muscle
• C. Cardiac muscle
• D. Striated muscle

Correct answer: B

Rationale: Smooth muscle is the correct answer. It is found in the walls of blood vessels and helps regulate blood flow by contracting and relaxing to adjust the diameter of the vessels. Skeletal muscle, found attached to bones, is responsible for voluntary movements and is not typically found in blood vessel walls. Cardiac muscle is specific to the heart and responsible for pumping blood, not found in blood vessel walls. Striated muscle, another term for skeletal muscle, is characterized by its striped appearance under a microscope but is not present in blood vessel walls.

5. Which of the following is a special property of water?

• A. Water does not easily flow through phospholipid bilayers.
• B. A water molecule's oxygen atom does not allow fish to breathe.
• C. Water is highly cohesive, which explains its high melting point.
• D. Water cannot self-hydrolyze and decompose into hydrogen and oxygen.

Correct answer: C

Rationale: Water is highly cohesive, meaning it is attracted to itself due to its hydrogen bonding properties. This cohesion is the reason why water has a high melting point compared to other liquids of similar molecular weight. It is crucial for the existence of life on Earth as it allows water to remain a liquid within a wide range of temperatures, providing a stable environment for biological processes to occur. Choices A, B, and D are incorrect. Water's cohesive property does not directly relate to its ability to flow through phospholipid bilayers, assist fish in breathing, or self-hydrolyze into hydrogen and oxygen.

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