Nursing Elites

1. Which enzyme found in saliva is responsible for breaking down carbohydrates into smaller molecules like sugars?

• A. Pepsin
• B. Amylase
• C. Lipase
• D. Trypsin

Correct answer: B

Rationale: The correct answer is B. Saliva contains an enzyme called amylase, which specifically targets carbohydrates and breaks them down into smaller molecules like sugars. Pepsin, choice A, is an enzyme found in the stomach that breaks down proteins, not carbohydrates. Lipase, choice C, is responsible for breaking down fats, not carbohydrates. Trypsin, choice D, is an enzyme that breaks down proteins in the small intestine, not carbohydrates. Therefore, choices A, C, and D are incorrect for this question.

2. What is the term for the mixture of reactants and products present during a chemical reaction?

• A. Solution
• B. Mixture
• C. Reaction mixture
• D. Precipitate

Correct answer: C

Rationale: The term 'reaction mixture' is used to describe the combination of both reactants and products that exist simultaneously during a chemical reaction. It encompasses not only the initial substances (reactants) but also the resulting compounds (products) formed throughout the reaction process. Choice A, 'Solution,' typically refers to a homogenous mixture where one substance is dissolved in another. Choice B, 'Mixture,' is a general term that does not specifically indicate the mix of reactants and products in a chemical reaction. Choice D, 'Precipitate,' specifically refers to the solid formed when two solutions react and a solid compound is produced.

3. 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.

4. In a scientific investigation, what is the first step?

• A. Analysis of results
• B. Drawing conclusions
• C. Formation of hypothesis
• D. Performing the experiment

Correct answer: C

Rationale: The correct answer is C: Formation of hypothesis. In a scientific investigation, forming a hypothesis is the initial step. A hypothesis is an educated guess or prediction based on existing knowledge and observations. It helps guide the experiment and provides a direction for the research process. Without a hypothesis, there is no specific aim or goal for the experiment. Choices A, B, and D are incorrect because they occur after the formation of a hypothesis. Analysis of results and drawing conclusions typically come after the experiment has been conducted, while performing the experiment is done to test the hypothesis formed at the beginning of the investigation.

5. What is the maximum volume of air that the lungs can hold after a full forced inhalation?

• A. Inspiratory capacity
• B. Tidal volume
• C. Total lung capacity
• D. Vital capacity

Correct answer: C

Rationale: Total lung capacity is the correct term for the maximum volume of air that the lungs can hold after a full forced inhalation. It represents the sum of all lung volumes, including tidal volume, inspiratory reserve volume, and expiratory reserve volume. Inspiratory capacity refers to the maximum volume of air inspired from the end-expiratory level. Tidal volume is the volume of air inspired or expired during normal breathing. Vital capacity is the maximum volume of air that can be exhaled after a maximum inhalation, not the total volume the lungs can hold.

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