CBSE Class 12 Chemistry Biomolecules MCQs Set C

Question. RNA and DNA are chiral molecules, their chirality is due to
(a) chiral bases
(b) chiral phosphate ester units
(c) D-sugar component
(d) L-sugar component.

Answer : C

Question. Chargaff’s rule states that in an organism
(a) amount of adenine (A) is equal to that of thymine (T) and the amount of guanine (G) is equal to that of cytosine (C)
(b) amount of adenine (A) is equal to that of guanine (G) and the amount of thymine (T) is equal to that of cytosine (C)
(c) amount of adenine (A) is equal to that of cytosine (C) and the amount of thymine (T) is equal to that of guanine (G)
(d) amounts of all bases are equal.

Answer : A

Question. Lipids are
(a) nucleic acids occurring in plants
(b) proteins occurring in animals
(c) carbohydrates occurring in plants
(d) fats of natural origin

Answer : D

Question. Which one of the following statements is true?
(a) Saponification of oil yields a diol
(b) Drying ofoil involves hydrolysis
(c) Addition of antioxidant to oil minimises rancidity
(d) Refining of oil involves hydrogenation

Answer : C

Question. Which base is present in RNA but not in DNA ?
(a) Uracil
(b) Cytosine
(c) Guanine
(d) Thymine

Answer : A

Question. The correct statement regarding RNA and DNA, respectively is
(a) the sugar component in RNA is a arabinose and the sugar component in DNA is ribose
(b) the sugar component in RNA is 2′-deoxyribose and the sugar component in DNA is arabinose
(c) the sugar component in RNA is arabinose and the sugar component in DNA is 2′-deoxyribose
(d) the sugar component in RNA is ribose and the sugar component in DNA is 2′-deoxyribose.

Answer : D

Question. Which one of the following sets of monosaccharides forms sucrose?
(a) a-D-galactopyranose and a-D-glucopyranose
(b) a-D-glucopyranose and b-D-fructofuranose
(c) b-D-glucopyranose and a-D-fructofuranose
(d) a-D-glucopyranose and b-D-fructopyranose

Answer : B

Question. In DNA, the linkages between different nitrogenous bases are
(a) phosphate linkage
(b) H-bonding
(c) glycosidic linkage
(d) peptide linkage.

Answer : B

Question. Which of the following is an amine hormone?
(a) Insulin
(b) Progesterone
(c) Thyroxine
(d) Oxypurin

Answer : C

Question. The segment of DNA which acts as the instrumental manual for the synthesis of the protein is
(a) ribose
(b) gene
(c) nucleoside
(d) nucleotide.

Answer : B

Question. Which one given below is a non-reducing sugar?
(a) Glucose
(b) Sucrose
(c) Maltose
(d) Lactose

Answer : B

Question. Which one of the following statements is not true regarding (+)–lactose? 
(a) On hydrolysis (+)–lactose gives equal amount of D(+)–glucose and D(+)–galactose.
(b) (+)–Lactose is a b-glucoside formed by the union of a molecule of D(+)–glucose and a molecule of D(+)–galactose.
(c) (+)–Lactose is a reducing sugar and does not exhibit mutarotation.
(d) (+)–Lactose, C₁₂H₂₂O₁₁ contains 8 –OH groups.

Answer : C

Question. Which of the following hormones contains iodine?
(a) Testosterone
(b) Adrenaline
(c) Thyroxine
(d) Insulin

Answer : C

Question. Which one of the following is a peptide hormone?
(a) Adrenaline
(b) Glucagon
(c) Testosterone
(d) Thyroxine

Answer : B

Question. Which one of the following does not exhibit the phenomenon of mutarotation?
(a) (+)–Sucrose
(b) (+)–Lactose
(c) (+)–Maltose
(d) (–)–Fructose

Answer : A

Question. A substance forms Zwitter ion. It can have functional groups
(a) —NH₂ , —COOH
(b) —NH₂, —SO₃H
(c) Both (a) and (b)
(d) None of the above 

Answer : C

Question. The chemical name of vitamin B₁ is
(a) ascorbic acid
(b) riboflavin
(c) pyridoxine
(d) thiamine

Answer : D

Question. Which of the following compounds is not of the lipid series ?
(a) Fat
(c) Oil
(b) Soap
(d) Lard

Answer : B

Question. a-D-glucose and b-D-glucose are
(a) epimers
(b) anomers
(c) enantiomers
(d) diastereomers.

Answer : B

Question. Which of the following is the sweetest sugar?
(a) Fructose
(b) Glucose
(c) Sucrose
(d) Maltose

Answer : A

Question. Fructose reduces Tollens’ reagent due to
(a) asymmetric carbons
(b) primary alcoholic group
(c) secondary alcoholic group
(d) enolisation of fructose followed by conversion to aldehyde by base.

Answer : D

Question. Number of chiral carbons in b-D-(+) glucose is
(a) five
(b) six
(c) three
(d) four.

Answer : D

Question. Glycolysis is
(a) oxidation of glucose to glutamate
(b) conversion of pyruvate to citrate
(c) oxidation of glucose to pyruvate
(d) conversion of glucose to haem.

Answer : C

Question. Which of the following statements about enzymes is true?
(a) Enzymes catalyse chemical reactions by increasing the activation energy.
(b) Enzymes are highly specific both in binding chiral substrates and in catalysing their reactions.
(c) Enzymes lack in nucleophilic groups.
(d) Pepsin is proteolytic enzyme.

Answer : B

Question. Which functional group participates in disulphide bond formation in proteins?
(a) Thiolacetone
(b) Thiol
(c) Thioether
(d) Thioester

Answer : B

Question. The purine base present in RNA is
(a) guanine
(b) thymine
(c) cytosine
(d) uracil

Answer : A

Question. Which one of the following is not present in RNA?
(a) Uracil
(b) Thymine
(c) Ribose
(d) Phosphate

Answer : B

Question. Glucose molecule reacts with X number of molecules of phenyl hydrazine to yield osazone. The value of X is
(a) two
(b) one
(c) four
(d) three.

Answer : D

Question. The oxidation of glucose is one of the most important reactions in a living cell. What is the number of ATP molecules generated in cells from one molecule of glucose?
(a) 28
(b) 38
(c) 12
(d) 18

Answer : B