Nursing Elites

1. In which type of cell would you expect to find a high concentration of lysosomes?

• A. Cardiac cells
• B. Glandular cells
• C. Immune cells
• D. Neurons

Correct answer: C

Rationale: The correct answer is C: Immune cells. Immune cells, such as macrophages, contain many lysosomes for breaking down pathogens. Lysosomes are organelles responsible for digestion and waste removal within the cell, and immune cells require a high concentration of lysosomes to aid in their defense mechanisms against pathogens. Choice A, Cardiac cells, is incorrect because lysosomes are not primarily abundant in cardiac cells. Choice B, Glandular cells, is incorrect as well since lysosomes are not specifically concentrated in glandular cells. Choice D, Neurons, is also incorrect because while lysosomes are present in neurons, they are not typically found in high concentrations compared to immune cells.

2. Which of the following hormones regulates calcium levels in the blood?

• A. Insulin
• B. Parathyroid hormone
• C. Thyroid hormone
• D. Glucagon

Correct answer: B

Rationale: The correct answer is B, Parathyroid hormone. Parathyroid hormone plays a crucial role in regulating calcium levels in the blood by increasing calcium levels when they are too low. This hormone acts on the bones, kidneys, and intestines to ensure proper calcium balance in the body. Insulin (choice A) is involved in glucose metabolism, not calcium regulation. Thyroid hormone (choice C) primarily regulates metabolism, and while it indirectly influences calcium levels, it is not the primary regulator. Glucagon (choice D) is involved in increasing blood glucose levels, not calcium regulation.

3. How does sunscreen protect the skin from harmful ultraviolet (UV) rays?

• A. By reflecting UV rays away from the skin
• B. By absorbing UV rays and converting them to heat
• C. By blocking UV rays completely
• D. By stimulating melanin production

Correct answer: B

Rationale: Sunscreen works by absorbing UV rays and converting them to heat. This mechanism helps to prevent the UV rays from penetrating the skin and causing damage such as sunburn, premature aging, and skin cancer. Reflecting UV rays away from the skin (option A) is not the primary function of sunscreen. While sunscreen does block UV rays, it does not do so completely (option C) as some UV rays may still penetrate the skin. Sunscreen does not stimulate melanin production (option D) as a means of protecting the skin from UV rays.

4. Examine the following decomposition reaction: ABC → ______. Which of the following is a possible set of products for this reaction?

• A. 2AB + C
• B. AB + CD
• C. A + BC
• D. B + C

Correct answer: C

Rationale: In a decomposition reaction, a single reactant breaks down into two or more products. For the decomposition of ABC, a plausible set of products is A + BC. This reaction represents the breakdown of ABC into two separate components: A and BC. The correct choice C aligns with the fundamental concept of decomposition reactions, where a compound disintegrates into simpler substances. Choices A, B, and D do not reflect a proper decomposition reaction as they do not demonstrate the breakdown of the original compound into distinct components.

5. What is the primary function of tight junctions, specialized regions between animal cells?

• A. Communication between cells
• B. Anchorage between cells
• C. Selective passage of materials
• D. All of the above

Correct answer: C

Rationale: The correct answer is C: Selective passage of materials. Tight junctions act as specialized structures between animal cells that create a barrier to the passage of materials. Their primary function is to prevent the leakage of extracellular fluid and control the selective passage of molecules between cells. This selective control is crucial in regulating the movement of substances across cell layers. Tight junctions do not directly facilitate communication between cells or provide anchorage between cells, as their main role is to regulate the passage of materials. Choices A and B are incorrect as tight junctions do not primarily serve for communication or anchorage between cells.

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