Explanation

Monosaccharides area simplest sugars and can be triose, tetrose, pentose, hexose, heptose, heptose for 3, 4, 5, 6 and 7 C-atom containing sugar respectively. Triose: Glyceraldehyde, dihydroxyacetone Tetrose: Erythrose, threose Pentose: Ribose, deoxyribose, ribulose Hexose: Glucose, fructose, mannose, galactose