Carbohydrates are composed of a combination of carbon, hydrogen, and which other element?
- A. oxygen.
- B. nitrogen.
- C. water.
- D. glucose.
Correct Answer: A
Rationale: Carbohydrates are composed of carbon, hydrogen, and oxygen. These three elements combine to form the basic structure of carbohydrates. Oxygen is an essential element in carbohydrates, contributing to their chemical composition. Choice B (nitrogen) is incorrect as nitrogen is not a typical component of carbohydrates. Choice C (water) is incorrect as water is not an element but a compound composed of hydrogen and oxygen. Choice D (glucose) is incorrect as glucose is a specific type of sugar, not an element found in the composition of carbohydrates.
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How many kilocalories (kcal) are provided by 35 g of fat?
- A. 140
- B. 245
- C. 315
- D. 360
Correct Answer: C
Rationale: Fat provides 9 kcal per gram, so 35 grams of fat provides 315 kcal. Therefore, the correct answer is C. Choice A (140) is incorrect because it doesn't consider the energy content of fat. Choice B (245) is incorrect as it miscalculates the kilocalories provided by 35g of fat. Choice D (360) is incorrect because it overestimates the kilocalories provided by 35g of fat.
A characteristic of saturated fats is that they are:
- A. mostly found in animal products.
- B. solid at room temperature.
- C. composed of many double bonds.
- D. found primarily in vegetable products.
Correct Answer: A
Rationale: The correct answer is A: 'mostly found in animal products.' Saturated fats are primarily found in animal products such as meat, dairy, and eggs. They are typically solid at room temperature. Choice B is incorrect because saturated fats are solid at room temperature, not liquid. Choice C is incorrect because saturated fats do not have double bonds; they have single bonds between carbon atoms. Choice D is incorrect because saturated fats are mainly found in animal products, not vegetable products.
Which mineral helps strengthen tooth enamel and prevent dental caries?
- A. Calcium
- B. Phosphorus
- C. Fluoride
- D. Zinc
Correct Answer: C
Rationale: The correct answer is C, Fluoride. Fluoride is a mineral known for its ability to strengthen tooth enamel and prevent dental caries. While calcium (Choice A) is essential for strong bones and teeth, it is not specifically known for preventing dental caries. Phosphorus (Choice B) is crucial for bone health but is not directly associated with preventing dental caries. Zinc (Choice D) is not typically recognized for strengthening tooth enamel or preventing dental caries.
What is necessary for photosynthesis to occur along with carbon dioxide and water?
- A. Glucose.
- B. Nitrogen.
- C. Chlorophyll.
- D. Hydrogen.
Correct Answer: C
Rationale: The correct answer is C: Chlorophyll. Chlorophyll is a pigment that is essential for photosynthesis as it absorbs light energy, allowing plants to convert carbon dioxide and water into glucose, a process crucial for plant growth. Glucose (choice A) is produced during photosynthesis and is not an ingredient necessary for the process itself. Nitrogen (choice B) is important for plant growth but is not a direct ingredient for photosynthesis. Hydrogen (choice D) is found in water, which is indeed one of the necessary ingredients for photosynthesis, but chlorophyll is specifically required to capture light energy for the process to occur.
What is one function of essential fatty acids?
- A. improve skin integrity.
- B. control lipid digestion.
- C. reduce blood clotting time.
- D. form chylomicrons.
Correct Answer: A
Rationale: Essential fatty acids play a crucial role in improving skin integrity by supporting the structure and function of cell membranes. This helps in maintaining healthy skin and promoting overall well-being. The other choices are incorrect because essential fatty acids do not directly control lipid digestion, reduce blood clotting time, or form chylomicrons.
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