Nursing Elites

1. Which of the following is an example of a polymer?

• A. Methane
• B. Ethanol
• C. Polyethylene
• D. Acetic acid

Correct answer: C

Rationale: The correct answer is C, Polyethylene. Polyethylene is a polymer composed of a large number of repeating ethylene units linked together, forming a long-chain molecule, characteristic of polymers. Methane, ethanol, and acetic acid are small organic molecules that do not demonstrate the repeating unit structure typical of polymers. Therefore, they are not examples of polymers.

2. Why are noble gas elements generally unreactive?

• A. They are too large and cannot form bonds easily.
• B. They lack valence electrons in their outermost shell.
• C. They have strong bonds within their own molecules.
• D. They have already achieved stable electron configurations.

Correct answer: D

Rationale: The correct answer is D. Noble gas elements are generally unreactive because they have already achieved stable electron configurations by having a full outer electron shell. This full shell makes them very stable and unlikely to gain, lose, or share electrons with other elements. Choices A, B, and C are incorrect because noble gases are not unreactive due to being too large to form bonds easily (A), lacking valence electrons in their outermost shell (B), or having strong bonds within their own molecules (C).

3. Which of the following is NOT a greenhouse gas?

• A. Carbon Dioxide
• B. Methane
• C. Oxygen
• D. Water Vapor

Correct answer: C

Rationale: A) Carbon Dioxide: Carbon dioxide is a greenhouse gas released into the atmosphere through various human activities such as burning fossil fuels and deforestation. It contributes to global warming by trapping heat in the atmosphere. B) Methane: Methane is another greenhouse gas released from sources like livestock, landfills, and natural gas production. It is more potent than carbon dioxide in trapping heat. C) Oxygen: Oxygen is not considered a greenhouse gas. It is a vital component of the Earth's atmosphere necessary for respiration and combustion, but it does not trap heat like greenhouse gases do. D) Water Vapor: Water vapor is a significant greenhouse gas that plays a crucial role in the Earth's climate system by trapping heat in the atmosphere. It is the most abundant greenhouse gas. Therefore, the correct answer is C) Oxygen, as it is not a greenhouse gas.

4. What is the function of valves in arteries?

• A. To maintain high blood pressure for the proper diffusion of nutrients in capillaries.
• B. To prevent backflow of blood due to high pressure away from the heart.
• C. As a vestigial trait from evolution, like the appendix, that serves no purpose.
• D. Valves are absent in arteries but present in veins.

Correct answer: B

Rationale: Valves in arteries serve the crucial function of preventing backflow of blood. Arteries carry blood at high pressure away from the heart, and the valves ensure that blood flows in one direction, towards the capillaries, to maintain efficient circulation. Without these valves, there would be a risk of blood flowing backward, compromising the effectiveness of blood circulation in the body. Choices A, C, and D are incorrect. Choice A incorrectly suggests that valves maintain high blood pressure for nutrient diffusion in capillaries, which is not their function. Choice C inaccurately compares valves to vestigial traits, like the appendix, implying they serve no purpose, which is untrue. Choice D is incorrect as valves are indeed present in arteries to regulate blood flow, not just in veins.

5. What is the muscular tube that transports sperm from the testes to the urethra called?

• A. Epididymis
• B. Vas deferens
• C. Seminal vesicle
• D. Cowper's gland

Correct answer: B

Rationale: The correct answer is the vas deferens. It is the muscular tube responsible for carrying sperm from the testes to the urethra. After sperm is produced in the testes, it moves to the epididymis for maturation and storage. The seminal vesicle contributes fluid to semen, but it is not the tube that transports sperm. Cowper's gland also adds fluid to semen but is not involved in transporting sperm. Therefore, the vas deferens is the accurate choice for the muscular tube that transports sperm.

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