Glucose and mannose are

The letter '$D$' in carbohydrates signifies

Which of the following forms osazone with phenylhydrazine?

$\beta-D-(+)-$Glucopyranose is represented by which of the following structures?

Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six-membered ring compounds) are insoluble in water. Explain.

Monosaccharides contain a carbonyl group and are hence classified as aldose or ketose. The number of carbon atoms present in the monosaccharide molecule is also considered for classification. In which class of monosaccharide will you place fructose?