Nursing Elites

1. Which of the following is the cardiac muscle layer that forms the bulk of the heart?

• A. Endocardium
• B. Epicardium
• C. Fibrous skeleton
• D. Myocardium

Correct answer: D

Rationale: The correct answer is D, Myocardium. The myocardium is the cardiac muscle layer that comprises the majority of the heart's muscle mass. It is responsible for the heart's contractions, allowing it to pump blood throughout the body. The endocardium is the innermost layer of the heart lining the chambers, while the epicardium is the outermost layer covering the heart. The fibrous skeleton provides structural support and serves as an attachment point for cardiac muscle fibers. Therefore, choices A, B, and C are incorrect as they do not represent the primary muscle layer of the heart.

2. Which of the following compounds often contains a carboxyl group?

• A. Carbohydrates
• B. Glycolipids
• C. Amino Acids
• D. DNA

Correct answer: C

Rationale: The correct answer is C: Amino Acids. Amino acids, the building blocks of proteins, contain both an amine group and a carboxyl group. The carboxyl group (-COOH) is crucial for the structure and function of proteins as it participates in peptide bond formation. Carbohydrates and DNA do not typically contain carboxyl groups as a functional group. Glycolipids consist of a carbohydrate chain linked to a lipid, but they do not inherently contain a carboxyl group.

3. What is the role of DNA in heredity?

• A. Provides energy for the cell
• B. Determines the structure and function of proteins
• C. Stores and transmits genetic information
• D. Controls cell division

Correct answer: C

Rationale: DNA (deoxyribonucleic acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It stores genetic information in the form of a code made up of four chemical bases: adenine (A), thymine (T), cytosine (C), and guanine (G). This genetic information is passed down from parents to offspring and is responsible for determining an organism's traits and characteristics. DNA's primary role is to store and transmit genetic information, making option C the correct answer. DNA does not provide energy for the cell (option A), determine the structure and function of proteins (option B), or control cell division (option D).

4. Which organ in the body is responsible for maintaining electrolyte balance and filtering waste from the blood?

• A. Liver
• B. Kidneys
• C. Heart
• D. Lungs

Correct answer: B

Rationale: The correct answer is B: Kidneys. The kidneys are responsible for filtering waste from the blood and maintaining electrolyte balance. They help regulate the body's fluid levels and produce urine as a means of waste elimination. The liver primarily plays a role in detoxification and metabolism, not in maintaining electrolyte balance or filtering waste from the blood. The heart is responsible for pumping blood, not for electrolyte balance or waste filtration. The lungs are primarily involved in gas exchange, not in maintaining electrolyte balance or filtering waste from the blood.

5. What is the main function of the respiratory system?

• A. To absorb nutrients
• B. To exchange gases
• C. To transport oxygen
• D. To regulate blood pressure

Correct answer: B

Rationale: The main function of the respiratory system is to exchange gases, primarily oxygen and carbon dioxide, between the body and the environment. Option A, 'To absorb nutrients,' is incorrect because the respiratory system is not involved in nutrient absorption. Option C, 'To transport oxygen,' is partially correct, but it doesn't encompass the complete role of gas exchange that includes both oxygen and carbon dioxide. Option D, 'To regulate blood pressure,' is incorrect as blood pressure regulation is primarily controlled by the cardiovascular system, not the respiratory system.

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