Nursing Elites

1. Which of the following organelles is responsible for food and water storage in the cell?

• A. Centriole
• B. Lysosome
• C. Ribosome
• D. Vacuole

Correct answer: D

Rationale: The correct answer is D, Vacuole. Vacuoles are membrane-bound organelles responsible for the storage of various substances such as food, water, and waste in a cell. They help maintain the cell's turgidity and regulate the movement of substances within the cell. Choice A, Centriole, is involved in cell division and organization of microtubules but not food and water storage. Choice B, Lysosome, contains digestive enzymes for breaking down cellular waste material and foreign invaders. Choice C, Ribosome, is involved in protein synthesis rather than storage of food and water.

2. Which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow?

• A. Skeletal muscle
• B. Smooth muscle
• C. Cardiac muscle
• D. Striated muscle

Correct answer: B

Rationale: Smooth muscle is the correct answer. It is found in the walls of blood vessels and helps regulate blood flow by contracting and relaxing to adjust the diameter of the vessels. Skeletal muscle, found attached to bones, is responsible for voluntary movements and is not typically found in blood vessel walls. Cardiac muscle is specific to the heart and responsible for pumping blood, not found in blood vessel walls. Striated muscle, another term for skeletal muscle, is characterized by its striped appearance under a microscope but is not present in blood vessel walls.

3. What happens to the speed of a sound wave when it travels from air to water?

• A. It increases because water is denser.
• B. It decreases because water is denser.
• C. It remains the same.
• D. Speed depends on the frequency, not the medium.

Correct answer: B

Rationale: When a sound wave travels from air to water, the speed of sound decreases because sound travels faster in denser mediums. Water, being denser than air, causes the speed of sound to slow down. Choice A is incorrect because sound travels faster in denser mediums, so the speed would not increase. Choice C is incorrect because the speed of sound changes when transitioning between different mediums. Choice D is incorrect because while frequency does affect sound, the medium it travels through also plays a significant role in determining the speed of sound.

4. Which of the following structures is responsible for producing insulin?

• A. Liver
• B. Pancreas
• C. Gallbladder
• D. Spleen

Correct answer: B

Rationale: The correct answer is B: Pancreas. The pancreas is the organ responsible for producing insulin. Insulin is a hormone that helps regulate blood sugar levels by allowing cells to take in glucose from the bloodstream. The liver (choice A) plays a role in regulating blood sugar levels through glycogen storage and release but does not produce insulin. The gallbladder (choice C) stores bile produced by the liver to aid in digestion and has no direct involvement in insulin production. The spleen (choice D) is involved in immune function and blood storage but not in the production of insulin.

5. Which process allows for the movement of large molecules, such as proteins and polysaccharides, across the cell membrane?

• A. Endocytosis
• B. Exocytosis
• C. Active transport
• D. Facilitated diffusion

Correct answer: A

Rationale: Endocytosis is the process by which cells engulf large molecules or particles by wrapping the cell membrane around them to form a vesicle that is brought into the cell. This mechanism facilitates the movement of large molecules like proteins and polysaccharides across the cell membrane. Exocytosis involves the release of large molecules or particles from the cell, opposite to the scenario described in the question. Active transport requires energy to move molecules against their concentration gradient and is not primarily used for transporting proteins and polysaccharides. Facilitated diffusion entails the movement of molecules aided by transport proteins but is not the primary mechanism for transporting large molecules such as proteins and polysaccharides.

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