Which monosaccharide only occurs naturally in foods in combination with another sugar as a disaccharide?

Correct Answer: B

Rationale: The correct answer is B, galactose. Galactose naturally occurs in foods only when it is combined with glucose to form lactose, a disaccharide found in milk. Fructose is a monosaccharide found in fruits and honey. Sucrose is a disaccharide composed of glucose and fructose, commonly known as table sugar. Maltose is a disaccharide formed by the combination of two glucose molecules.

Correct Answer: D

Rationale: Fructose is a sugar naturally found in honey and fruit. While bread contains carbohydrates, it does not primarily consist of fructose. Gelatin desserts are more likely to contain added sugars like sucrose rather than fructose. Sugar-coated cereals typically contain sucrose or other added sugars, not just fructose. Therefore, the correct answer is honey and fruit as they naturally contain fructose.

Correct Answer: D

Rationale: Fructose is known to be the sweetest among naturally occurring sugars. While glucose, sucrose, and galactose also have sweet tastes, fructose is commonly perceived as the sweetest due to its higher level of sweetness. Glucose is a simple sugar found in many carbohydrates; sucrose is table sugar composed of glucose and fructose; galactose is a component of lactose found in dairy products. However, when comparing the sweetness levels of these sugars, fructose stands out as the sweetest.

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.

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.