Which of the following are two examples of disaccharides?

Disaccharides are carbohydrates formed by the combination of two monosaccharides through a glycosidic bond. The correct answer identifies two common disaccharides: sucrose and lactose.

Sucrose is made up of glucose and fructose, while lactose consists of glucose and galactose. Both of these combinations illustrate the key feature of disaccharides being formed from two simpler sugar units. Sucrose is often found in table sugar, and lactose is found in milk, making them easily recognizable and significant carbohydrates in our diet.

The other options consist of monosaccharides or do not represent disaccharides. Glucose and fructose are individual monosaccharides, while ribose and xylose are also monosaccharides. Mannose and galactose, while they are monosaccharides themselves, do not pair to form a disaccharide in the same way as sucrose and lactose do. Recognizing these structures helps clarify understanding of how sugars are classified and their significance in biology and nutrition.