Nursing Elites

1. Which of the following items is NOT a primary function of a healthy immune system?

• A. The immune system helps the body avoid infections.
• B. The immune system detects infections.
• C. The immune system eliminates infections.
• D. The immune system creates infections.

Correct answer: D

Rationale: The correct answer is D. The primary functions of a healthy immune system do not involve creating infections. A healthy immune system helps the body avoid infections by providing defense mechanisms, detects infections by recognizing harmful pathogens, and eliminates infections by attacking and clearing out pathogens. Creating infections goes against the protective role of the immune system and is not a function it performs. Therefore, choices A, B, and C are correct functions of a healthy immune system, while choice D is incorrect.

2. Which of the following substances is a common base found in household products?

• A. Sodium chloride (NaCl)
• B. Ammonia (NH₃)
• C. Vinegar
• D. Lemon juice

Correct answer: B

Rationale: The correct answer is B, Ammonia (NH₃). Ammonia is commonly found in household products and is used in cleaning agents due to its alkaline properties. Sodium chloride (NaCl) is a common salt and not a base. Vinegar is acetic acid, which is acidic in nature. Lemon juice contains citric acid, making it acidic as well. Therefore, ammonia is the only base among the choices provided.

3. 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.

4. What is the endoplasmic reticulum?

• A. A network of tubules that transport proteins and lipids throughout the cell
• B. A sac-like structure that stores water and nutrients
• C. The site of protein synthesis
• D. The site of cellular respiration

Correct answer: A

Rationale: A) The endoplasmic reticulum (ER) is a network of tubules that are involved in the transport of proteins and lipids throughout the cell. It plays a crucial role in protein synthesis, folding, and transport within the cell. The ER can be further divided into rough ER, which has ribosomes attached to its surface and is involved in protein synthesis, and smooth ER, which is involved in lipid metabolism and detoxification. Therefore, option A is the most accurate description of the endoplasmic reticulum compared to the other options provided. B) A sac-like structure that stores water and nutrients does not accurately describe the endoplasmic reticulum. While some organelles like vacuoles or vesicles may store water and nutrients, the ER's primary function is not storage. C) The site of protein synthesis is partially

5. After a person eats birthday cake, which of the following enzymes is needed to break down the sucrose in the cake?

• A. Lactase
• B. Maltase
• C. Peptidase
• D. Sucrase

Correct answer: D

Rationale: Sucrase is the correct enzyme needed to break down sucrose into its component sugars, glucose, and fructose. Lactase is responsible for breaking down lactose, maltase for maltose, and peptidase for proteins; therefore, they are not the enzymes required to digest sucrose specifically. In the context of digesting birthday cake, which contains sucrose, sucrase is the enzyme needed for this particular sugar.

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