How many monosaccharide units are present in a disaccharide?

• A. 3
• B. 2
• C. 1
• D. 4

Answer: (B)

Verified step by step guidance

1. Understand the definition of a disaccharide: A disaccharide is a carbohydrate composed of two monosaccharide units joined together by a glycosidic bond.
2. Recall that monosaccharides are the simplest form of carbohydrates, such as glucose or fructose, and serve as the building blocks for larger carbohydrates.
3. Visualize the structure of a disaccharide, such as sucrose or lactose, which consists of exactly two monosaccharide units chemically linked.
4. Note that the number of monosaccharide units in a disaccharide is always two, as the prefix 'di-' indicates two units.
5. Conclude that the correct answer to the question is based on the definition of a disaccharide, which contains two monosaccharide units.