Nursing Elites

1. The energy released in nuclear fusion originates from:

• A. The fission of heavy nuclei
• B. The binding energy released during the fusion of light nuclei
• C. Electronic transitions within atoms
• D. Matter-antimatter annihilation

Correct answer: B

Rationale: The correct answer is B: 'The binding energy released during the fusion of light nuclei.' Nuclear fusion is the process where light nuclei combine to form a heavier nucleus, releasing energy in the form of binding energy. This energy comes from the conversion of mass into energy as per Einstein's famous equation E=mc^2. In contrast, option A refers to nuclear fission, where heavy nuclei split into lighter nuclei, releasing energy. Option C is related to atomic energy levels, and option D involves the complete conversion of matter into energy, not specific to nuclear fusion. Therefore, the energy released in nuclear fusion originates from the binding energy released during the fusion of light nuclei.

2. A lab test result shows a blood glucose level of 5.5 millimoles per liter (mmol/L). What is the equivalent level in milligrams per deciliter (mg/dL)?

• A. 55 mg/dL
• B. 5.5 mg/dL
• C. 0.55 mg/dL
• D. 550 mg/dL

Correct answer: A

Rationale: This requires a double conversion: millimoles to milligrams and liters to deciliters. 1 millimole is equal to 180.15 milligrams, and 1 liter is equal to 10 deciliters. Multiply the glucose level (5.5 mmol/L) by the conversion factor for millimoles to milligrams (180.15 mg/mmol) and then divide by the conversion factor for liters to deciliters (10 dL/L): 5.5 mmol/L * 180.15 mg/mmol / 10 dL/L ≈ 55 mg/dL.

3. Which of the following can weaken the immune system and increase susceptibility to infections?

• A. Regular exercise
• B. Balanced diet
• C. Chronic stress
• D. Adequate sleep

Correct answer: C

Rationale: Chronic stress can weaken the immune system by increasing the production of stress hormones like cortisol, which can suppress immune function over time. Prolonged stress can also lead to inflammation, making the body more vulnerable to infections. It is important to manage stress levels through relaxation techniques, exercise, and seeking support to maintain a healthy immune system.

4. Which of the following organs is NOT directly involved in the mechanical breakdown of food?

• A. Mouth
• B. Stomach
• C. Small intestine
• D. Esophagus

Correct answer: D

Rationale: The correct answer is D, esophagus. The esophagus is a muscular tube that connects the mouth to the stomach, but it is not directly involved in the mechanical breakdown of food. The mouth is responsible for the initial mechanical breakdown of food through chewing, the stomach further breaks down food through muscular contractions, and the small intestine aids in the digestion process. However, the esophagus primarily serves to transport chewed food from the mouth to the stomach via peristaltic movements, without actively breaking down the food itself.

5. 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.

6. Which element is a component of baking soda and is important for maintaining pH balance in the body?

• A. Potassium
• B. Sodium
• C. Calcium
• D. Sodium bicarbonate

Correct answer: D

Rationale: Sodium bicarbonate acts as a base and helps regulate pH in various biological systems

Similar Questions