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. What type of muscle is found in the walls of the heart?

• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle
• D. Voluntary muscle

Correct answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle is the specialized muscle found in the walls of the heart. It contracts involuntarily to pump blood throughout the body, ensuring circulation. Smooth muscle is typically found in organs like the intestines and blood vessels, aiding in their functions. Skeletal muscle is attached to bones and plays a vital role in movement and posture. Voluntary muscle is a general term for skeletal muscles that are under conscious control, unlike cardiac muscle which contracts involuntarily to maintain the heart's continuous pumping action.

3. What is a primary function of red blood cells?

• A. To fight infection
• B. To carry oxygen
• C. To produce antibodies
• D. To transport waste

Correct answer: B

Rationale: The main function of red blood cells is to carry oxygen from the lungs to all the body's tissues and organs, where it is needed for cellular functions and metabolism. This process is essential for sustaining life and providing energy to cells. Choice A is incorrect because fighting infection is primarily done by white blood cells. Choice C is incorrect because antibody production is mainly carried out by specialized white blood cells. Choice D is incorrect as the primary role of red blood cells is not to transport waste, but rather to transport oxygen and some carbon dioxide.

4. Which of the following best describes the term homeostasis?

• A. The ability to maintain a constant body temperature
• B. The ability to maintain a stable internal environment
• C. The ability to increase body temperature when cold
• D. The ability to regulate blood glucose levels

Correct answer: B

Rationale: The correct answer is B, 'The ability to maintain a stable internal environment.' Homeostasis refers to the body's ability to regulate and maintain a stable internal environment, which includes variables like body temperature, pH levels, and fluid balance. It involves processes that help keep the body's internal conditions within a narrow range, despite external changes. While maintaining body temperature is a component of homeostasis, it is not the complete definition of the term. Choice C, 'The ability to increase body temperature when cold,' is incorrect as homeostasis aims to maintain stability rather than promoting temperature increases in response to external conditions. Choice D, 'The ability to regulate blood glucose levels,' is also incorrect as this is a specific function related to glucose homeostasis, which is a part of overall homeostatic processes but not the sole definition of homeostasis itself.

5. How does lymph move through the lymphatic vessels?

• A. By the pumping action of the heart
• B. Due to muscle contractions and breathing movements
• C. Through one-way valves within the vessels
• D. All of the above

Correct answer: C

Rationale: Lymph moves through the lymphatic vessels due to the presence of one-way valves within the vessels. These valves prevent the backflow of lymph and help propel the fluid forward as muscles contract and relax or due to breathing movements. Unlike blood circulation, the lymphatic system does not rely on the pumping action of the heart to move lymph. Choice A is incorrect because lymphatic circulation does not depend on the pumping action of the heart. Choice B is partly correct as muscle contractions and breathing movements do assist in propelling lymph, but the primary mechanism is the presence of one-way valves within the vessels, making choice C the most accurate answer. Choice D is incorrect as not all options listed contribute to how lymph moves through the lymphatic vessels.

Similar Questions