Nursing Elites

1. Which of the following is a unit of power?

• A. Newton-meter (N·m)
• B. Joule (J)
• C. Watt (W)
• D. Kilogram (kg)

Correct answer: C

Rationale: The correct answer is C: Watt (W). Power is the rate at which work is done or energy is transferred. The unit of power is the watt (W), named after James Watt, the inventor of the steam engine. A Newton-meter (N·m) is a unit of torque, Joule (J) is a unit of energy, and Kilogram (kg) is a unit of mass, not power. Therefore, choices A, B, and D are incorrect as they represent units of torque, energy, and mass, respectively, and not power.

2. Which transport mechanism uses vesicles to move materials out of the cell?

• A. Endocytosis
• B. Active transport
• C. Diffusion
• D. Exocytosis

Correct answer: D

Rationale: Exocytosis is the transport mechanism that uses vesicles to move materials out of the cell. Vesicles carry substances to the cell membrane, fuse with it, and release their contents outside the cell. This process is essential for secreting molecules such as hormones, enzymes, or neurotransmitters. Endocytosis, on the other hand, is the process of bringing materials into the cell by engulfing them in vesicles. Active transport involves the movement of molecules across a cell membrane against their concentration gradient, requiring energy. Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration.

3. Why is the lining of the stomach covered with rugae?

• A. Rugae increase the output of gastric juices.
• B. Rugae increase the surface area of the stomach.
• C. Rugae increase the permeability of the stomach walls.
• D. Rugae increase the types of nutrients that can diffuse.

Correct answer: B

Rationale: Rugae are folds in the stomach lining that increase its surface area. This increased surface area allows for more efficient digestion and absorption of nutrients in the stomach. Choice A is incorrect because rugae do not directly affect the output of gastric juices. Choice C is incorrect because rugae do not impact the permeability of the stomach walls. Choice D is incorrect because rugae do not influence the types of nutrients that can diffuse.

4. Which of the following cell organelles is the site of lipid synthesis?

• A. smooth endoplasmic reticulum
• B. ribosome
• C. rough endoplasmic reticulum
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is the smooth endoplasmic reticulum. This organelle lacks ribosomes on its surface, unlike the rough endoplasmic reticulum, which is involved in protein synthesis. The enzymes present in the smooth endoplasmic reticulum are responsible for synthesizing lipids such as phospholipids and steroids. Choice B, ribosomes, are responsible for protein synthesis and not lipid synthesis. Choice C, rough endoplasmic reticulum, is involved in protein synthesis due to the presence of ribosomes. Choice D, Golgi apparatus, is responsible for modifying, sorting, and packaging proteins for secretion, not lipid synthesis.

5. What is the process of separating a mixture based on the different boiling points of its components called?

• A. Filtration
• B. Chromatography
• C. Distillation
• D. Centrifugation

Correct answer: C

Rationale: Distillation is the process of separating a mixture based on the different boiling points of its components. During distillation, the mixture is heated to vaporize the component with the lowest boiling point first. The vapor is then cooled and condensed back into a liquid, allowing for the collection of fractions with different boiling ranges. This technique is effective for separating components that have significantly different boiling points. Filtration (Choice A) is a method used to separate solids from liquids or gases using a filter medium. Chromatography (Choice B) is a technique used to separate components of a mixture based on their differential affinities to a stationary phase and a mobile phase. Centrifugation (Choice D) is a process of separating particles from a solution based on differences in size, shape, density, and viscosity by spinning the mixture at high speeds.

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