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. What property of a substance refers to its ability to undergo a chemical change and form new substances with different properties?

• A. Density
• B. Mass
• C. Reactivity
• D. Volume

Correct answer: C

Rationale: Reactivity is the property of a substance that describes its ability to undergo a chemical change and form new substances with different properties. Density (A), mass (B), and volume (D) are physical properties of a substance and do not directly relate to its ability to undergo chemical changes. Density is mass per unit volume, mass is the amount of matter in a substance, and volume is the space occupied by a substance.

3. What tool helps scientists identify and classify organisms based on their shared characteristics?

• A. Binomial nomenclature
• B. Cladistics
• C. Dichotomous key
• D. Domain-based classification

Correct answer: C

Rationale: A) Binomial nomenclature is a system used to give each organism a two-part scientific name (genus and species) but does not help in identifying or classifying organisms based on shared characteristics. B) Cladistics is a method of classification based on evolutionary relationships and shared characteristics, but it is not a tool used for identifying organisms. C) A dichotomous key is a tool that helps scientists identify and classify organisms based on their shared characteristics by presenting a series of choices leading the user to the correct identification. D) Domain-based classification is a system of grouping organisms into three domains (Bacteria, Archaea, Eukarya) based on molecular and genetic similarities, but it is not a tool used for identifying organisms based on shared characteristics.

4. Which vitamin is essential for blood clotting?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin K
• D. Vitamin D

Correct answer: C

Rationale: Vitamin K is essential for blood clotting as it plays a crucial role in the synthesis of clotting factors in the liver. Deficiency in vitamin K can result in impaired blood clotting and excessive bleeding. Vitamin K is necessary for the activation of proteins that are involved in the blood clotting process, making it a vital nutrient for maintaining proper hemostasis. Vitamin A (Choice A) is important for vision and immune function, Vitamin C (Choice B) is crucial for collagen synthesis and antioxidant protection, and Vitamin D (Choice D) is essential for calcium absorption and bone health. However, when it comes to blood clotting specifically, Vitamin K is the key vitamin involved.

5. Which vitamin is synthesized in the skin upon exposure to sunlight?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin E

Correct answer: C

Rationale: Vitamin D is synthesized in the skin upon exposure to sunlight. When the skin is exposed to sunlight, a form of cholesterol in the skin is converted into vitamin D3 (cholecalciferol) through a series of chemical reactions. Vitamin D plays a crucial role in calcium absorption and bone health. Choice A, Vitamin A, is not synthesized in the skin upon exposure to sunlight; it is obtained through dietary sources. Choice B, Vitamin C, is not synthesized in the skin upon exposure to sunlight either. Vitamin C is obtained through dietary sources like fruits and vegetables. Choice D, Vitamin E, is not synthesized in the skin upon exposure to sunlight. Vitamin E is a fat-soluble vitamin that acts as an antioxidant and is obtained through dietary sources like nuts, seeds, and vegetable oils.

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