Nursing Elites

1. Which indicator is commonly used to distinguish between acidic and basic solutions?

• A. Methyl orange
• B. Phenolphthalein
• C. Universal indicator
• D. All of the above are common indicators.

Correct answer: B

Rationale: Phenolphthalein is commonly used to differentiate between acidic and basic solutions. It changes color, turning pink in basic solutions and remaining colorless in acidic solutions due to a specific pH range. While methyl orange and universal indicator are also indicators used for pH testing, phenolphthalein is especially known for its distinctive color change in response to acidic and basic solutions, making it the correct choice. Methyl orange is typically used in titrations for a sharp color change at a specific pH, and the universal indicator is a mixture of indicators displaying a range of colors depending on the pH value, not specifically tailored to acidic and basic distinctions.

2. Which of the following equations correctly models the relationship between x and y when y is three times x?

• A. y = 3x
• B. x = 3y
• C. y = x + 3
• D. y = x / 3

Correct answer: A

Rationale: The correct equation that models the relationship between x and y when y is three times x is y = 3x. This equation represents that y is equal to three times x. Choice B (x = 3y) incorrectly reverses the relationship, stating that x is equal to three times y. Choice C (y = x + 3) and Choice D (y = x / 3) do not correctly represent a relationship where y is three times x, making them incorrect choices.

3. Which of the following describes a graph that represents a proportional relationship?

• A. The graph has a slope of 2,500 and a y-intercept of 250
• B. The graph has a slope of 1,500 and a y-intercept of -150
• C. The graph has a slope of 2,000 and a y-intercept of 0
• D. The graph has a slope of -1,800 and a y-intercept of -100

Correct answer: C

Rationale: A graph that has a y-intercept of 0 indicates a proportional relationship because the starting value is 0, and no amount is added to or subtracted from the term containing the slope. In this case, choice C is correct as it has a y-intercept of 0, which aligns with the characteristics of a proportional relationship. Choices A, B, and D have non-zero y-intercepts, indicating a starting value other than 0, which does not represent a proportional relationship.

4. Which of the following statements best defines an organelle?

• A. Layer of polysaccharides outside the plasma membrane of cells.
• B. Abnormal infectious proteins.
• C. Specialized structures within a cell.
• D. Collection of tissues used to serve a specific function.

Correct answer: C

Rationale: The correct answer is C: 'Specialized structures within a cell.' An organelle is a specialized subunit within a cell that has a specific function. Organelles are membrane-bound structures found within the cytoplasm of eukaryotic cells, each performing distinct roles that contribute to the overall functioning of the cell. Choices A, B, and D are incorrect. Option A describes the glycocalyx, which is a layer of polysaccharides outside the plasma membrane of cells. Option B refers to prions, abnormal infectious proteins. Option D defines an organ, a collection of tissues used to serve a specific function, rather than an organelle within a cell.

5. What is the process by which decomposers break down organic matter?

• A. Photosynthesis
• B. Bioremediation
• C. Decomposition
• D. Nitrification

Correct answer: C

Rationale: A) Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy to produce glucose from carbon dioxide and water. This process is not related to the breakdown of organic matter by decomposers. B) Bioremediation is the use of living organisms to clean up contaminated environments. While it involves the use of microorganisms to break down pollutants, it is not specifically focused on breaking down organic matter. C) Decomposition is the process by which decomposers such as bacteria, fungi, and other organisms break down organic matter into simpler substances. This process is essential for nutrient recycling in ecosystems. D) Nitrification is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of nitrite to nitrate by nitrifying bacteria. This process is part of the nitrogen cycle and is not directly related to the breakdown of organic matter.

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