Nursing Elites

1. In experimental design, which variable is measured as a possible effect and is plotted on the y-axis?

• A. Independent, x
• B. Independent, y
• C. Dependent, x
• D. Dependent, y

Correct answer: D

Rationale: The correct answer is D: 'Dependent, y.' In experimental design, the dependent variable is the outcome that is being measured or observed as a result of changes in the independent variable. It is typically plotted on the y-axis of a graph to represent the effect or response to the changes in the independent variable. Choice A 'Independent, x' is incorrect because the independent variable is the variable manipulated by the experimenter and is usually plotted on the x-axis. Choice B 'Independent, y' is incorrect as the independent variable is not plotted on the y-axis. Choice C 'Dependent, x' is incorrect because the dependent variable is not typically plotted on the x-axis in experimental design.

2. At which step in the scientific method might a scientist create a model?

• A. Hypothesis
• B. Data analysis
• C. Experimentation
• D. Conclusion

Correct answer: A

Rationale: In the scientific method, scientists often create models during the hypothesis stage. Creating models at this stage helps visualize or simulate ideas before proceeding to experimentation and data analysis. Models are valuable tools that allow scientists to conceptualize and test their ideas before conducting experiments to gather data and draw conclusions. Therefore, the correct answer is A. Choice B, data analysis, occurs after experiments have been conducted and data has been collected, making it an incorrect choice. Choice C, experimentation, involves conducting tests and observations based on the hypothesis, but the creation of models typically happens before this stage. Choice D, conclusion, is the final step where scientists interpret the results and draw implications, making it an inappropriate step for creating a model.

3. Where is keratin found?

• A. It is a protein-digesting enzyme released by the stomach.
• B. It is released in the neuromuscular junction.
• C. It is a protein found in the hypodermis.
• D. It is a protein found in hair.

Correct answer: D

Rationale: Keratin is a structural protein found in hair, skin, and nails, providing strength and protection. It forms the main structural component of hair, making choice D the correct answer. Choices A, B, and C are incorrect because keratin is not an enzyme released by the stomach, not released in the neuromuscular junction, and not found in the hypodermis. Remember that keratin is primarily associated with structural support in epithelial cells.

4. What is the primary function of the placenta during pregnancy?

• A. Produce insulin
• B. Facilitate gas exchange between mother and fetus
• C. Excrete waste products from the fetus
• D. All of the above

Correct answer: B

Rationale: The primary function of the placenta during pregnancy is to facilitate the exchange of oxygen and carbon dioxide between the mother and the fetus. This ensures that the fetus receives oxygen and eliminates carbon dioxide, supporting its growth and development. While the placenta also allows for the transfer of nutrients and waste products between the mother and the fetus, its main role is to ensure proper gas exchange. Therefore, choices A, C, and D are incorrect as the primary role of the placenta is not to produce insulin or excrete waste products from the fetus. Selecting the correct answer, choice B, highlights the crucial role of the placenta in providing oxygen to the fetus and removing carbon dioxide, which are essential for fetal well-being and development.

5. How does RNA polymerase differ from DNA polymerase?

• A. Both enzymes are identical in function and structure.
• B. RNA polymerase does not require a primer to initiate RNA synthesis.
• C. RNA polymerase can synthesize both RNA and DNA.
• D. RNA polymerase can only synthesize RNA, unlike DNA polymerase.

Correct answer: B

Rationale: Rationale: A) This statement is incorrect. RNA polymerase and DNA polymerase are not identical in function and structure. They have different roles in the cell. B) This statement is correct. Unlike DNA polymerase, RNA polymerase does not require a primer to initiate RNA synthesis. RNA polymerase can start the synthesis of RNA de novo. C) This statement is incorrect. RNA polymerase is specialized for synthesizing RNA, not DNA. DNA polymerase is responsible for synthesizing DNA. D) This statement is correct. RNA polymerase can only synthesize RNA, while DNA polymerase is responsible for synthesizing DNA.

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