NEET Practice Questions (MCQs) with Answers & Solutions

The NCERT text clearly states: 'The carbohydrates are stored in animal body as glycogen. It is also known as animal starch because its structure is similar to amylopectin and is rather more highly branched.'

The NCERT text states: 'All those carbohydrates which reduce Fehling’s solution and Tollens’ reagent are referred to as reducing sugars. All monosaccharides whether aldose or ketose are reducing sugars.' Option o4 is also true for monosaccharides (by definition), but o3 describes a specific chemical property shared by all monosaccharides as 'reducing sugars'.

The NCERT text mentions: 'Cellulose occurs exclusively in plants and it is the most abundant organic substance in plant kingdom. It is a predominant constituent of cell wall of plant cells.'

The NCERT text states: 'Glucose is an aldohexose...' The prefix 'aldo-' indicates an aldehyde group, and '-hexose' indicates six carbon atoms (hexa-).

The NCERT text states: 'For example acetic acid (CH$_3$COOH) fits into this general formula, C$_2$(H$_2$O)$_2$ but is not a carbohydrate.' Rhamnose is a carbohydrate but doesn't fit the formula. Maltose and Cellulose are carbohydrates.

The NCERT text states: 'The most common sugar, used in our homes is named as sucrose...'

The NCERT text states: 'It [glycogen] is present in liver, muscles and brain.'

The NCERT text explains: 'Despite having the aldehyde group, glucose does not give Schiff’s test and it does not form the hydrogensulphite addition product with NaHSO$_3$... This behaviour could not be explained by the open chain structure (I) for glucose. It was proposed that one of the —OH groups may add to the —CHO group and form a cyclic hemiacetal structure. This explains the absence of —CHO group...'

The NCERT text states: "'D' before the name of glucose represents the configuration whereas '(+)' represents dextrorotatory nature of the molecule." It further elaborates: 'In the case of carbohydrates, this refers to their relation with a particular isomer of glyceraldehyde... the –OH group lies on right hand side in the structure.' This specifically refers to the lowest asymmetric carbon.

The NCERT text states: 'Glucose gets oxidised to six carbon carboxylic acid (gluconic acid) on reaction with a mild oxidising agent like bromine water. This indicates that the carbonyl group is present as an aldehydic group.' While reaction with hydroxylamine confirms a carbonyl group, bromine water specifically indicates an aldehyde.