Nursing Elites

1. What is the function of water in photosynthesis?

• A. Combine with carbon dioxide
• B. Absorb light energy
• C. Supply electrons in the light reactions
• D. Transport hydrogen ions in the dark reactions

Correct answer: C

Rationale: The correct answer is C: 'Supply electrons in the light reactions.' In photosynthesis, water is split during the light reactions of photosynthesis, releasing electrons that are used in the formation of ATP and NADPH, crucial for the synthesis of glucose. Choice A is incorrect because water does not combine with carbon dioxide in photosynthesis. Choice B is incorrect as water does not absorb light energy directly. Choice D is incorrect because the transportation of hydrogen ions mainly occurs in the electron transport chain, which is part of the light reactions, not the dark reactions.

2. 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.

3. Which one is not a reactant in photosynthesis?

• A. Water
• B. Light energy
• C. Glucose
• D. Carbon dioxide

Correct answer: C

Rationale: The correct answer is C: Glucose. Glucose is not a reactant in photosynthesis but a product. During photosynthesis, plants use water, carbon dioxide, and light energy as reactants to produce glucose and oxygen. Water is essential for the process of photosynthesis, along with carbon dioxide and light energy. Light energy is necessary for the light-dependent reactions to occur, which eventually leads to the production of glucose. Carbon dioxide is absorbed by plants through tiny pores called stomata and is used in the Calvin cycle to synthesize glucose. Therefore, glucose is the product of photosynthesis, not a reactant.

4. Which cellular structure is largely protective in function?

• A. Mitochondrion
• B. Vacuole
• C. Cell membrane
• D. Ribosome

Correct answer: C

Rationale: The correct answer is C: Cell membrane. The cell membrane, also known as the plasma membrane, is largely protective in function as it serves as a selectively permeable barrier that surrounds the cell, providing structural support and helping to maintain cell integrity. It regulates the movement of substances in and out of the cell, thus protecting the cell from harmful external factors while allowing essential nutrients to enter. Mitochondrion (choice A) is responsible for energy production, not primarily protective. Vacuole (choice B) is mainly involved in storage and transport. Ribosome (choice D) is involved in protein synthesis, not protective functions.

5. Which type of sugar is a disaccharide?

• A. Sucrose
• B. Fructose
• C. Glucose
• D. Galactose

Correct answer: A

Rationale: The correct answer is A, Sucrose. Sucrose is a disaccharide composed of one molecule of glucose and one molecule of fructose. When glucose and fructose combine, they form sucrose. Choice B, Fructose, is a monosaccharide, not a disaccharide. Choice C, Glucose, is also a monosaccharide, not a disaccharide. Choice D, Galactose, is another monosaccharide and not a disaccharide.

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