Nursing Elites

1. When sugar is heated, it breaks down into carbon and water vapor. This is an example of a:

• A. Combination reaction
• B. Decomposition reaction
• C. Double displacement reaction
• D. Single displacement reaction

Correct answer: B

Rationale: The correct answer is B: Decomposition reaction. When sugar is heated, it undergoes a decomposition reaction where it breaks down into simpler substances, carbon, and water vapor. In a decomposition reaction, a single compound breaks down into two or more simpler substances. This process is the opposite of a combination reaction where two or more substances combine to form a new compound. Choice A, Combination reaction, is incorrect because a combination reaction involves the combination of two or more substances to form a new compound, which is the opposite of what happens when sugar breaks down. Choices C and D, Double displacement reaction and Single displacement reaction, are incorrect as they involve different mechanisms where the atoms or ions of the reactants are exchanged, which is not the case in the breakdown of sugar into carbon and water vapor.

2. Where is keratin found?

• A. It is a protein-digesting enzyme released by the stomach.
• B. It is released in the neuromuscular junction.
• C. It is a protein found in the hypodermis.
• D. It is a protein found in hair.

Correct answer: D

Rationale: Keratin is a structural protein found in hair, skin, and nails, providing strength and protection. It forms the main structural component of hair, making choice D the correct answer. Choices A, B, and C are incorrect because keratin is not an enzyme released by the stomach, not released in the neuromuscular junction, and not found in the hypodermis. Remember that keratin is primarily associated with structural support in epithelial cells.

3. Which blood vessels carry deoxygenated blood from the body back to the right atrium of the heart?

• A. Arteries
• B. Veins
• C. Capillaries
• D. Venules

Correct answer: B

Rationale: Veins are the blood vessels that carry deoxygenated blood from the body back to the heart. Arteries transport oxygenated blood away from the heart. Capillaries are the smallest blood vessels where gas exchange occurs between blood and tissues. Venules are small veins that connect capillaries to larger veins, but they do not directly carry deoxygenated blood back to the heart.

4. What functional group is present in esters?

• A. Hydroxyl
• B. Carbonyl
• C. Ester
• D. Amine

Correct answer: C

Rationale: The functional group present in esters is -COO-, which represents a carbonyl group bonded to an oxygen atom. This group is responsible for the characteristic fruity aroma of esters. Choice A, 'Hydroxyl,' refers to -OH, which is a characteristic group of alcohols, not esters. Choice B, 'Carbonyl,' is a broad term that includes various compounds with a C=O group, but specifically in esters, it is a carbonyl group bonded to an oxygen atom. Choice D, 'Amine,' refers to compounds containing a nitrogen atom bonded to hydrogen atoms or alkyl groups, which is not present in esters. Therefore, the correct answer is 'C: Ester.'

5. Which of the following is NOT part of the circulatory system?

• A. Kidneys
• B. Heart
• C. Blood
• D. Blood vessels

Correct answer: A

Rationale: The correct answer is A: Kidneys. The kidneys are part of the urinary system, responsible for filtering waste and maintaining fluid balance in the body. In the circulatory system, the heart pumps blood, blood carries oxygen and nutrients, and blood vessels transport blood throughout the body. Choices B, C, and D are all components of the circulatory system, making the kidneys the correct choice as it belongs to the urinary system.

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