Nursing Elites

1. What is the difference between DNA and RNA?

• A. Both are double-stranded.
• B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
• C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
• D. Both are identical molecules.

Correct answer: B

Rationale: Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

2. When magnesium metal reacts with hydrochloric acid, hydrogen gas is produced. What evidence suggests a chemical reaction is occurring?

• A. A change in color
• B. The formation of a gas
• C. Dissolving in a liquid
• D. No change in temperature

Correct answer: B

Rationale: The correct answer is B: 'The formation of a gas.' When magnesium metal reacts with hydrochloric acid, hydrogen gas is produced as one of the products. The formation of a gas is a clear indicator of a chemical reaction taking place. This is known as a gas evolution reaction, where a gas is produced as a result of a chemical reaction. The other options do not specifically indicate a chemical reaction. A change in color or dissolving in a liquid could occur in physical changes as well, and no change in temperature does not necessarily rule out a chemical reaction as some reactions are endothermic or exothermic.

3. Which of the following is evidence that the controlling process is effective?

• A. The things that were planned are done
• B. Physicians do not complain.
• C. Employees are contended
• D. There is an increase in customer satisfaction rate.

Correct answer: A

Rationale: The correct answer is A: 'The things that were planned are done.' This is evidence that the controlling process is effective because it indicates that the organization is able to execute its plans successfully. When planned tasks and activities are completed as intended, it shows that the controlling function is ensuring that operations are on track and that deviations are being corrected. The completion of planned tasks also demonstrates that resources are being effectively utilized and that performance is being monitored and controlled. The other options do not directly relate to the effectiveness of the controlling process. Physicians not complaining, employees being contented, and an increase in customer satisfaction rate could be influenced by various factors and may not necessarily be solely attributed to the effectiveness of the controlling process.

4. What is the feedback mechanism in the endocrine system that helps maintain hormone balance?

• A. Positive feedback, where a hormone stimulates its own release
• B. Negative feedback, where a hormone suppresses its own release
• C. Cascade effect, where one hormone triggers the release of another
• D. Dual hormone system, where two hormones work together

Correct answer: B

Rationale: The correct answer is B: Negative feedback, where a hormone suppresses its own release. In the endocrine system, negative feedback is a crucial mechanism that helps maintain hormone balance. When hormone levels rise, they signal the body to decrease further hormone production, preventing an excess. This ensures that hormone levels stay within a narrow range, promoting stability and homeostasis. Positive feedback (option A) would lead to an amplification of hormone release, which is not ideal for maintaining balance. Cascade effect (option C) involves a sequential activation of hormones but does not directly regulate hormone levels. Dual hormone system (option D) refers to two hormones working together but doesn't specifically address the feedback mechanism for maintaining hormone balance.

5. During a healthy heartbeat, the P wave on an ECG represents

• A. The repolarization of the ventricles.
• B. The electrical conduction through the AV node.
• C. The contraction phase of the ventricles (systole)
• D. The depolarization of the atria.

Correct answer: D

Rationale: The correct answer is D: The P wave on an ECG represents the depolarization of the atria. During a healthy heartbeat, the P wave is the first positive deflection seen on the ECG and reflects the initiation of the electrical impulse in the atria, leading to atrial contraction. It is followed by the QRS complex, which represents the depolarization of the ventricles. Options A, B, and C are incorrect because the P wave specifically corresponds to atrial depolarization, not repolarization of the ventricles, electrical conduction through the AV node, or ventricular contraction. Understanding the sequence of electrical events in the heart as represented on an ECG is crucial for interpreting cardiac function and identifying potential abnormalities.

6. A car accelerates from rest. What happens to its kinetic energy and work done on it?

• A. Both kinetic energy and work done increase
• B. Kinetic energy increases, but work done remains constant.
• C. Work done increases, but kinetic energy remains constant.
• D. Both kinetic energy and work done remain constant.

Correct answer: A

Rationale: During acceleration, the car's speed increases, leading to rising kinetic energy. Simultaneously, the force applied to accelerate the car does work on it, increasing the work done.

Similar Questions