Synthesis of each molecule of glucose in photosynthesis involves:

How can you say that glucose is a cyclic compound?

Given below are two statements:
Statement $I:$ Fructose does not contain an aldehydic group but still reduces Tollen's reagent.
Statement $II:$ In the presence of base,fructose undergoes rearrangement to give glucose.
In the light of the above statements,choose the correct answer from the options given below:

$L$-isomer of tetrose $X$ $(C_4H_8O_4)$ gives positive Schiff's test and has two chiral carbons. On acetylation,$X$ yields triacetate. $X$ also undergoes the following reactions:
$X$ $\xrightarrow{HNO_3} A$ $\xrightarrow{NaBH_4} \underset{\text{Chiral compound}}{B}$
$X$ is $.......$.

What are glucose and mannose to each other?

In which of the following compounds are all the monosaccharide units $NOT$ joined by a $C_1-O-C_4$ glycosidic linkage?