Nursing Elites

1. Which structure in the respiratory system is responsible for gas exchange?

• A. Trachea
• B. Alveoli
• C. Bronchi
• D. Diaphragm

Correct answer: B

Rationale: The alveoli in the lungs are responsible for gas exchange. Alveoli have a rich blood supply and thin walls, enabling the exchange of oxygen and carbon dioxide. Oxygen diffuses into the blood from the alveoli, while carbon dioxide diffuses out. The trachea functions as an air passage, bronchi are the main airways into the lungs, and the diaphragm is the primary muscle involved in breathing by aiding in lung expansion and contraction, but they are not directly responsible for gas exchange like the alveoli.

2. Which property of matter remains constant regardless of changes in gravity?

• A. Mass
• B. Weight
• C. Volume
• D. Density

Correct answer: A

Rationale: Mass is a measure of the amount of matter in an object and remains constant regardless of changes in gravity. Weight, on the other hand, is the force of gravity acting on an object and can vary depending on the strength of gravity. Volume is the amount of space an object occupies, and density is the mass per unit volume of a substance, both of which can change with changes in gravity. Therefore, mass is the property that remains the same regardless of variations in gravitational force. Choice B, Weight, changes with gravity as it is a force dependent on gravity. Choices C and D, Volume and Density, can be affected by changes in gravity as they are related to the space an object occupies and the mass per unit volume, respectively.

3. What is the function of the myelin sheath in a neuron?

• A. To transmit electrical impulses
• B. To insulate and speed up electrical signals
• C. To produce neurotransmitters
• D. To protect the neuron from damage

Correct answer: B

Rationale: The myelin sheath serves to insulate neurons and accelerate the transmission of electrical signals along the axon. This insulation helps in the efficient conduction of nerve impulses by preventing signal loss or leakage. Choice A is incorrect because the myelin sheath does not transmit electrical impulses itself but rather helps in the conduction. Choice C is incorrect as the myelin sheath is not responsible for producing neurotransmitters. Choice D is also incorrect as the primary function of the myelin sheath is not to protect the neuron from damage. Therefore, the correct answer is B, as it accurately describes the function of the myelin sheath in a neuron.

4. With which genotype would the recessive phenotype appear if the dominant allele is marked with 'A' and the recessive allele is marked with 'a'?

• A. AA
• B. aa
• C. Aa
• D. aA

Correct answer: B

Rationale: The recessive phenotype appears when an individual has two copies of the recessive allele. In this case, the recessive allele is marked with 'a.' Therefore, the genotype 'aa' would display the recessive phenotype as both alleles are recessive. Choice A (AA) has two dominant alleles, choice C (Aa) has one dominant and one recessive allele, and choice D (aA) represents the same genotype as Aa due to the principle of allele dominance.

5. Which of the following is NOT a major division of the nervous system?

• A. Peripheral nervous system
• B. Central nervous system
• C. Somatic nervous system
• D. Autonomic nervous system

Correct answer: C

Rationale: The correct answer is C: Somatic nervous system. The major divisions of the nervous system are the central nervous system, which includes the brain and spinal cord, and the peripheral nervous system, which includes all the nerves outside of the central nervous system. The somatic nervous system, which controls voluntary movements and reflexes, is a part of the peripheral nervous system. The autonomic nervous system is another subdivision of the peripheral nervous system that regulates involuntary functions like heart rate and digestion. Therefore, the somatic nervous system is not a major division of the nervous system, making it the correct answer.

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