Answer: (B) Fructose
Explanation: Fructose is a ketose sugar because it contains a ketone group, while glucose, galactose, and mannose are aldose sugars, which have an aldehyde group.

Answer: (D) Isomers
Explanation: Glucose and fructose are both simple sugars with the same molecular formula (C₆H₁₂O₆) but different structural arrangements. This makes them isomers of each other.

Answer: (C) Raffinose
Explanation: Raffinose is an oligosaccharide that is indeed commonly found in human milk, whereas sucrose, lactose, and cellulose are either disaccharides or polysaccharides with different roles or sources.

Answer: (C) Cellular recognition
Explanation: Oligosaccharides are important for cellular recognition because they are involved in the formation of glycoproteins and glycolipids on the cell surface, which help cells identify and interact with each other.

Answer: (C) Lactose
Explanation:  Lactose is a disaccharide made up of glucose and galactose. Maltose consists of two glucose units, sucrose is made of glucose and fructose, and raffinose contains glucose, fructose, and galactose.

Answer: (C) Starch
Explanation: Starch is the polysaccharide primarily used by plants to store energy. Cellulose provides structural support, glycogen is used for energy storage in animals, and chitin is found in the exoskeletons of arthropods.

Answer: (B) Cellulose
Explanation: Cellulose is a polysaccharide that forms the primary structural component of plant cell walls, giving them rigidity and strength. Starch and glycogen serve as energy storage, while dextran is not a major structural component in plants.

Answer: (C) Animals
Explanation: Glycogen is the primary storage form of carbohydrates in animals. It is stored mainly in the liver and muscles, providing a quick energy source when needed. Plants store carbohydrates as starch, not glycogen.

Answer: (C) Insects and fungi
Explanation: Chitin is a strong and flexible polysaccharide that forms the exoskeleton of insects and the cell walls of fungi. It provides structural support in these organisms.

Answer: (B) Building muscle
Explanation: Carbohydrates primarily provide energy, spare protein from being used for energy, and help in fat metabolism. However, building muscle is primarily the role of proteins, not carbohydrates.