Final answer:
Glucose and galactose are aldoses, and fructose is a ketose.
Step-by-step explanation:
Glucose, galactose, and fructose are isomeric monosaccharides (hexoses) with the same chemical formula but slightly different structures. Glucose and galactose are aldoses, while fructose is a ketose. Aldoses are sugars containing an aldehydic group, and ketoses are sugars containing a ketonic group. Therefore, glucose and galactose are aldoses, and fructose is a ketose.