Nursing Elites

1. 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.

2. Which of the following is an example of an unsaturated fatty acid?

• A. Stearic acid
• B. Palmitic acid
• C. Oleic acid
• D. Butyric acid

Correct answer: C

Rationale: Oleic acid is an example of an unsaturated fatty acid because it contains one or more double bonds in its hydrocarbon chain, leading to kinks in the chain structure. This unsaturation gives it a lower melting point compared to saturated fatty acids. Stearic acid (A), Palmitic acid (B), and Butyric acid (D) are examples of saturated fatty acids as they do not contain any double bonds in their hydrocarbon chains, leading to a straight structure and higher melting points.

3. Which organelle provides energy for cellular functions?

• A. Nucleus
• B. Cell membrane
• C. Mitochondria
• D. Cytoplasm

Correct answer: C

Rationale: The correct answer is C, Mitochondria. Mitochondria are often referred to as the powerhouse of the cell as they produce energy in the form of ATP through cellular respiration. This process is essential for various cellular functions, making mitochondria crucial for energy production within the cell. Choice A, Nucleus, is incorrect as the nucleus is responsible for housing the cell's genetic material and controlling cellular activities but not for energy production. Choice B, Cell membrane, is incorrect as it is primarily involved in maintaining cell integrity and regulating the passage of substances in and out of the cell, not in energy production. Choice D, Cytoplasm, is incorrect as it is the jelly-like substance that fills the cell and is the site of many metabolic pathways, but it is not the specific organelle responsible for energy production.

4. The body's first line of defense against pathogens is the innate immune system. Which of the following is NOT a component of the innate immune system?

• A. Physical barriers like skin and mucous membranes
• B. Phagocytes that engulf and destroy pathogens
• C. Inflammatory response to isolate and contain infection
• D. Production of antibodies specific to a particular pathogen

Correct answer: D

Rationale: The production of antibodies specific to a particular pathogen is a function of the adaptive immune system, not the innate immune system. The innate immune system provides immediate, non-specific defense mechanisms against pathogens, including physical barriers, phagocytes, and inflammatory responses. Choices A, B, and C are all correct components of the innate immune system. Physical barriers like skin and mucous membranes act as the first line of defense, preventing pathogens from entering the body. Phagocytes are specialized cells that engulf and destroy pathogens, while the inflammatory response helps isolate and contain infections to prevent their spread.

5. Which structure in the respiratory system is responsible for gas exchange?

• A. Trachea
• B. Alveoli
• C. Bronchi
• D. Diaphragm

Correct answer: B

Rationale: The alveoli in the lungs are responsible for gas exchange. Alveoli have a rich blood supply and thin walls, enabling the exchange of oxygen and carbon dioxide. Oxygen diffuses into the blood from the alveoli, while carbon dioxide diffuses out. The trachea functions as an air passage, bronchi are the main airways into the lungs, and the diaphragm is the primary muscle involved in breathing by aiding in lung expansion and contraction, but they are not directly responsible for gas exchange like the alveoli.

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