Final answer:
Oligosaccharides are complex carbohydrates made up of 3-10 monosaccharides, important for cell recognition and adhesion.
Step-by-step explanation:
Oligosaccharides are complex carbohydrates that consist of a small number of monosaccharides. Specifically, they are composed of 3-10 monosaccharides linked together by glycosidic bonds. This defines oligosaccharides in contrast to monosaccharides, which cannot be hydrolyzed into simpler sugars, and polysaccharides, which are made up of more than ten monosaccharide units. Oligosaccharides play an important role in cell recognition and cell adhesion, influencing biological processes such as defining blood types and immune responses.