Nursing Elites

1. Which type of cells are found in the hair bulb and are responsible for hair growth?

• A. Basal
• B. Epidermal
• C. Epithelial
• D. Merkel

Correct answer: C

Rationale: The correct answer is C: Epithelial. The hair bulb contains actively growing epithelial cells responsible for hair growth. Basal cells are located in the basal layer of the epidermis, not specifically in the hair bulb, making choice A incorrect. Epidermal cells are part of the outer layer of the skin, so choice B is incorrect. Merkel cells are related to touch sensations in the skin, not hair growth, making choice D incorrect.

2. Antigenic variation, a common strategy used by some viruses, allows them to:

• A. Produce toxins
• B. Evade the immune system
• C. Survive outside a host
• D. Replicate rapidly

Correct answer: B

Rationale: Antigenic variation is a strategy used by some viruses to evade the host's immune response. By constantly changing their surface antigens, viruses can avoid recognition and destruction by the immune system. This allows the virus to persist in the host and continue replicating, leading to prolonged infection and potential transmission to other hosts. Antigenic variation does not directly involve the production of toxins, survival outside a host, or rapid replication, making options A, C, and D incorrect in this context.

3. What are the four main types of macromolecules that are essential for life?

• A. Carbohydrates, lipids, proteins, and nucleic acids
• B. Carbohydrates, proteins, fats, and vitamins
• C. Minerals, vitamins, proteins, and fats
• D. Carbohydrates, lipids, proteins, and hormones

Correct answer: A

Rationale: The correct answer is A: Carbohydrates, lipids, proteins, and nucleic acids. These four types of macromolecules are essential for life as they serve crucial roles in various cellular processes. Carbohydrates are the primary energy source for cells and provide structural support. Lipids function as energy storage molecules and are essential components of cell membranes. Proteins have diverse functions in cellular processes, acting as enzymes, structural components, and more. Nucleic acids, like DNA and RNA, carry genetic information and are crucial for protein synthesis. Choices B, C, and D are incorrect because they include elements like fats, vitamins, minerals, and hormones, which are not the main types of macromolecules essential for life.

4. Antibodies, crucial for immune defense, are produced by:

• A. Neutrophils
• B. Lymphocytes
• C. Monocytes
• D. Basophils

Correct answer: B

Rationale: Antibodies are produced by a specific type of lymphocyte known as B cells. B cells are a critical component of the adaptive immune system and are responsible for producing antibodies in response to pathogens. Neutrophils, monocytes, and basophils are types of white blood cells that are part of the innate immune response and do not have the function of producing antibodies. Neutrophils are primarily involved in phagocytosis, monocytes differentiate into macrophages and dendritic cells for antigen presentation, while basophils are involved in allergic reactions and parasitic infections.

5. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?

• A. Molality (m)
• B. Molarity (M)
• C. Weight percent (%)
• D. Parts per million (ppm)

Correct answer: A

Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.

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