Nursing Elites

1. What is the function of the cell membrane?

• A. To protect the cell and control what enters and exits
• B. To store energy
• C. To produce proteins
• D. To synthesize lipids

Correct answer: A

Rationale: The cell membrane, also known as the plasma membrane, serves as a protective barrier for the cell, separating the internal environment of the cell from the external environment. It is selectively permeable, meaning it controls the passage of substances in and out of the cell. This regulation of what enters and exits the cell is crucial for maintaining the cell's internal environment and ensuring proper functioning. Options B, C, and D are incorrect because storing energy, producing proteins, and synthesizing lipids are functions carried out by other cellular structures such as mitochondria, ribosomes, and endoplasmic reticulum, respectively, not the cell membrane.

2. The dark, round structures observed within some bacterial cells are most likely:

• A. Ribosomes
• B. Flagella
• C. Endospores
• D. Capsules

Correct answer: C

Rationale: Endospores are the correct answer. Endospores are dark, round structures observed within some bacterial cells. They are highly resistant dormant structures formed by certain bacteria in response to harsh environmental conditions. Ribosomes are not dark, round structures within bacterial cells; they are responsible for protein synthesis. Flagella are long, whip-like appendages used for movement and are not dark, round structures within bacterial cells. Capsules are outer layers of polysaccharides that some bacteria produce for protection and adherence, not dark, round structures within bacterial cells.

3. What are the three layers of the heart?

• A. Endocardium, myocardium, epicardium
• B. Pericardium, endocardium, myocardium
• C. Epicardium, myocardium, endocardium
• D. Pericardium, myocardium, endocardium

Correct answer: C

Rationale: The correct answer is C: Epicardium, myocardium, endocardium. The heart wall consists of three layers: the outer layer is the epicardium, the middle muscular layer is the myocardium, and the inner layer is the endocardium. Understanding the layers of the heart is essential for comprehending its structure and function. Choices A, B, and D are incorrect because they do not present the layers of the heart in the correct order. The pericardium is the outermost layer that surrounds the heart, but it is not part of the heart wall itself. Therefore, choices B and D are incorrect. Choice A is incorrect as it presents the layers in the wrong order, starting with the endocardium instead of the epicardium, which is the outermost layer.

4. What is the body's primary defense against pathogens?

• A. Phagocytes
• B. Antibodies
• C. Memory B cells
• D. T lymphocytes

Correct answer: A

Rationale: The correct answer is A: Phagocytes. Phagocytes are the body's first line of defense against pathogens. They are innate immune cells that engulf and digest foreign particles like bacteria and viruses, preventing infections. Phagocytes act as the initial barrier to invading pathogens and are part of the innate immune response. Choice B, Antibodies, are produced by B cells in the adaptive immune response. Choice C, Memory B cells, are also part of the adaptive immune response and provide a faster and stronger response upon re-exposure to pathogens. Choice D, T lymphocytes, are part of the adaptive immune response, particularly involved in cell-mediated immunity.

5. Which part of the brain controls breathing and heart rate?

• A. Cerebrum
• B. Medulla oblongata
• C. Thalamus
• D. Cerebellum

Correct answer: B

Rationale: The medulla oblongata is the correct answer because it is responsible for controlling involuntary functions such as breathing and heart rate. The cerebrum (Choice A) is primarily associated with higher brain functions like thinking and voluntary movements, not with regulating basic bodily functions like breathing and heart rate. The thalamus (Choice C) serves as a relay station for sensory information but is not directly involved in controlling breathing and heart rate. The cerebellum (Choice D) plays a role in coordination and balance, not in regulating respiratory and cardiac functions.

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