Nursing Elites

1. A collection of organs working together to perform a specific physiological function is known as a(n):

• A. Tissue
• B. Organ system
• C. Organelle
• D. Organ

Correct answer: B

Rationale: An organ system is a group of organs that work together to perform specific functions in the body. Each organ within the system has a unique role, but they collaborate to achieve a common physiological function. This collaboration allows the body to carry out complex processes efficiently, demonstrating the interconnectedness and interdependence of different organs within the system. Choice A, 'Tissue,' refers to a group of cells that work together to perform a specific function, not a collection of organs. Choice C, 'Organelle,' is a subunit within a cell that has a specific function and is not a collection of organs. Choice D, 'Organ,' is a single structure composed of different tissues that performs a specific function, not a collection of organs working together.

2. Which structure in the lungs is the site of gas exchange?

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

Correct answer: B

Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from inhaled air diffuses into the bloodstream, while carbon dioxide from the blood is released into the alveoli to be exhaled. The trachea (Choice A) is the windpipe that carries air to and from the lungs, but it is not involved in gas exchange. Bronchioles (Choice C) are small air passages within the lungs that branch off from the bronchi, leading air to the alveoli but not directly involved in gas exchange. The diaphragm (Choice D) is a muscle below the lungs that helps in breathing by expanding and contracting the chest cavity, but it is not the site of gas exchange.

3. A substance is only considered acidic if it has a pH less than what?

• A. 12
• B. 9
• C. 7
• D. 4

Correct answer: C

Rationale: A substance is considered acidic if its pH is less than 7. pH values below 7 indicate acidity, while pH values above 7 indicate alkalinity or basicity. Substances with a pH less than 7 are categorized as acidic, not above it. Therefore, a substance is classified as acidic if its pH is less than 7, making choice C the correct answer. Choices A, B, and D are incorrect because a pH of 12, 9, and 4, respectively, are all above 7, and therefore not indicative of acidity.

4. What is the structure surrounding and protecting the testes, maintaining the optimal temperature for sperm production?

• A. Epididymis
• B. Vas deferens
• C. Scrotum
• D. Prostate gland

Correct answer: C

Rationale: The scrotum is the structure that surrounds and protects the testes. It plays a vital role in maintaining an optimal temperature for sperm production by adjusting the distance of the testes from the body to regulate the effects of external temperature changes. This mechanism helps to safeguard the viability and quality of sperm by ensuring they develop at the right temperature. The epididymis (Choice A) is a coiled tube where sperm mature and are stored, not the structure surrounding the testes. The vas deferens (Choice B) is a duct that carries sperm from the testes to the urethra, not the protective structure around the testes. The prostate gland (Choice D) is part of the male reproductive system, responsible for secreting fluids that nourish and protect sperm, but it is not the structure that surrounds and protects the testes for sperm production.

5. The fossil record shows that dinosaurs with feathers existed millions of years before birds. This is evidence for

• A. Convergent evolution (unrelated organisms evolving similar traits)
• B. Divergent evolution (related organisms evolving different traits)
• C. Coevolution (two species influencing each other's evolution)
• D. The extinction of dinosaurs due to an asteroid impact

Correct answer: A

Rationale: The fossil record indicates that dinosaurs had feathers before birds, suggesting convergent evolution. Convergent evolution occurs when unrelated organisms independently evolve similar traits to adapt to similar environmental pressures. In this case, both dinosaurs and birds developed feathers for flight or insulation purposes, even though they are not closely related. This evidence supports the concept of convergent evolution rather than divergent evolution, coevolution, or the extinction of dinosaurs due to an asteroid impact. Therefore, the correct answer is A, as it best explains the scenario where dinosaurs with feathers existed before birds, showcasing the concept of unrelated organisms evolving similar traits independently.

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