Nursing Elites

1. What phenomenon explains the formation of rainbows in the sky?

• A. Diffraction
• B. Interference
• C. Refraction and dispersion of sunlight by water droplets
• D. Reflection from clouds

Correct answer: C

Rationale: Rainbows are formed due to the refraction and dispersion of sunlight by water droplets in the atmosphere. When sunlight enters a water droplet, it is refracted, then internally reflected, and finally refracted again as it exits the droplet. This dispersion of light into its component colors creates the beautiful rainbow we see in the sky. Choice A, diffraction, involves bending of light around obstacles or through narrow openings, not the splitting of light into colors as seen in rainbows. Choice B, interference, refers to the phenomenon where two or more light waves overlap and interact, producing a pattern of light and dark bands, which is not the case with rainbows. Choice D, reflection from clouds, does not accurately describe the process involved in the formation of rainbows through refraction and dispersion of light by water droplets.

2. When a person pushes a box across the floor, which of the following forces is NOT doing work?

• A. The person's pushing force
• B. The normal force from the floor
• C. The gravitational force on the box
• D. The frictional force between the box and the floor

Correct answer: B

Rationale: The normal force from the floor is perpendicular to the direction of motion of the box, so it does not contribute to the work being done. Work is only done by forces acting in the direction of motion of an object. In this case, the normal force is acting at a right angle to the motion, hence it does not perform any work on the box. The person's pushing force, the gravitational force, and the frictional force are all acting in the direction of motion of the box, so they contribute to the work being done in moving the box across the floor.

3. The adrenal glands are part of which system?

• A. Immune system
• B. Endocrine system
• C. Lymphatic system
• D. Respiratory system

Correct answer: B

Rationale: The correct answer is B: Endocrine system. The adrenal glands are part of the endocrine system, not the immune, lymphatic, or respiratory system. The endocrine system is responsible for producing and regulating hormones that control various bodily functions. The adrenal glands specifically produce hormones like cortisol and adrenaline, which are critical for the body's response to stress and metabolic processes. The immune system is responsible for defending the body against infections and diseases, the lymphatic system is involved in immunity and fluid balance, and the respiratory system is responsible for gas exchange in the body. Therefore, choices A, C, and D are incorrect in the context of the adrenal glands.

4. Which of the following best describes the term homeostasis?

• A. The ability to maintain a constant body temperature
• B. The ability to maintain a stable internal environment
• C. The ability to increase body temperature when cold
• D. The ability to regulate blood glucose levels

Correct answer: B

Rationale: The correct answer is B, 'The ability to maintain a stable internal environment.' Homeostasis refers to the body's ability to regulate and maintain a stable internal environment, which includes variables like body temperature, pH levels, and fluid balance. It involves processes that help keep the body's internal conditions within a narrow range, despite external changes. While maintaining body temperature is a component of homeostasis, it is not the complete definition of the term. Choice C, 'The ability to increase body temperature when cold,' is incorrect as homeostasis aims to maintain stability rather than promoting temperature increases in response to external conditions. Choice D, 'The ability to regulate blood glucose levels,' is also incorrect as this is a specific function related to glucose homeostasis, which is a part of overall homeostatic processes but not the sole definition of homeostasis itself.

5. Which type of carbohydrate is the main component of the cell wall in plant cells?

• A. Starch
• B. Glucose
• C. Cellulose
• D. Chitin

Correct answer: C

Rationale: The correct answer is 'Cellulose.' Cellulose is the main component of the cell wall in plant cells, providing structural support and rigidity. Starch, while a carbohydrate, is a storage form of glucose in plants and not a component of the cell wall. Glucose is a simple sugar that can be used as an energy source but is not the main component of the cell wall. Chitin is a structural carbohydrate found in the exoskeleton of arthropods and fungi, not in plant cell walls.

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