Final answer:
Two monosaccharides can combine through a dehydration reaction to form a disaccharide with a glycosidic bond. For X unique monosaccharides, the number of possible disaccharides is X(X-1)/2, representing the number of unique pairs that can be made.
Step-by-step explanation:
Monosaccharides are the simplest form of carbohydrates and consist of single sugar units like glucose. When two monosaccharides undergo a dehydration reaction, they form a disaccharide, which is a type of carbohydrate made up of two monosaccharide molecules linked together. The bond formed between the two monosaccharides is known as a glycosidic bond.
Each pair of monosaccharides can react with each other to form one unique disaccharide; hence, if we have X monosaccharides, number of possible disaccharides is determined by the number of unique pairs that can be formed from X monosaccharides. In mathematical terms, the number of unique pairs from X items is calculated as X(X-1)/2. This only holds true when all X monosaccharides are different from each other and can react to form a disaccharide. If some of the monosaccharides are identical, the number of unique disaccharides will be less.