Nursing Elites

1. Which structure might be described as a core of nucleic acid surrounded by a protein coat?

• A. RNA
• B. Virus
• C. Blue-green alga
• D. Saprophyte

Correct answer: B

Rationale: A virus can be described as a core of nucleic acid (either RNA or DNA) surrounded by a protein coat, known as a capsid. This structure distinguishes viruses from other microorganisms such as blue-green algae (Cyanobacteria), fungi known as saprophytes, or individual RNA molecules. Viruses depend on a host cell to replicate and are considered non-living entities due to their inability to carry out metabolic functions independently.

2. Which is not one of the raw materials needed for cellular respiration?

• A. ADP
• B. Phosphate
• C. Water
• D. Glucose

Correct answer: C

Rationale: Water is not one of the raw materials needed for cellular respiration. The essential raw materials for cellular respiration include glucose (which is broken down to produce energy), oxygen, and ADP (adenosine diphosphate) and phosphate (which are necessary for the formation of ATP, the energy currency of cells). While water is crucial for many cellular processes and makes up a significant portion of cells, it is not directly involved as a raw material in the cellular respiration process.

3. Which of the following is a tertiary consumer?

• A. Owl
• B. Shrew
• C. Grasshopper
• D. Wheat

Correct answer: A

Rationale: The correct answer is A, Owl. Tertiary consumers are organisms that feed on secondary consumers, which, in turn, feed on primary consumers. Owls are considered tertiary consumers because they primarily feed on animals such as rodents, which are secondary consumers. Shrew (choice B) is a secondary consumer, feeding on insects and worms, placing it at a lower trophic level than the owl. Grasshopper (choice C) is a primary consumer, feeding on plants. Wheat (choice D) is not a consumer in the food chain but a plant.

4. How does an enzyme work on a chemical reaction that occurs in a substrate?

• A. An enzyme slows down the chemical reaction.
• B. An enzyme speeds up the chemical reaction.
• C. An enzyme has no effect on the chemical reaction.
• D. An enzyme stops most chemical reactions.

Correct answer: B

Rationale: Enzymes are biological catalysts that facilitate chemical reactions by lowering the activation energy required for the reaction to occur. This allows the reaction to proceed more quickly and efficiently. Enzymes do not change the overall outcome of the reaction, but they significantly increase the rate at which it takes place. Therefore, choice B, 'An enzyme speeds up the chemical reaction,' is the correct answer. Choices A, C, and D are incorrect because enzymes do not slow down, have no effect, or stop chemical reactions; instead, they accelerate the process by lowering the activation energy.

5. Why is polarity the most important characteristic of water?

• A. the results of the polarity are hydrogen bonding, a high specific heat value, and its versatile solvent properties
• B. the results of the polarity are covalent bonding, a low specific heat value, and its versatile solvent properties
• C. the results of the polarity are ionic bonding, a high specific heat value, and its versatile solvent properties
• D. the results of the polarity are hydrogen bonding, a low specific heat value, and its versatile solvent properties

Correct answer: A

Rationale: Polarity is the most important characteristic of water because it results in hydrogen bonding, a high specific heat value, and its versatile solvent properties. These unique properties enable water to form hydrogen bonds with other substances, resist temperature changes, and dissolve a wide variety of solutes, making it essential for life processes. Choice B is incorrect because water exhibits hydrogen bonding, not covalent bonding. Choice C is incorrect as water does not form ionic bonds. Choice D is incorrect because water has a high, not low, specific heat value, which is vital for its role in temperature regulation.

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