MCQ on Nucleotide

A nucleotide refers to an organic molecule with a basic composition of a nitrogenous base, pentose sugar and phosphate.

DNA and RNA are polynucleotides, it contains a chain of nucleotides monomers with different nitrogenous bases. Nucleotides are important for carrying out different metabolic and physiological activities. ATP (Adenosine triphosphate) functions as the energy currency of cells. Nucleotides form various coenzymes and cofactors, like NAD, NADP, FAD, coenzyme A, etc. and these are important for many metabolic processes.

Q1. A phosphodiester bond is located in

a) Nucleic acids in a nucleotide

b) Fatty acids in a diglyceride 

c) Amino acids in a polypeptide

d) Monosaccharides in a polysaccharide.

Ans. Here, the correct answer is (a) nucleic acids in a nucleotide.

Q2. Name the Uridine present in RNA 

a) nucleoside

b) purine

c) pyrimidine

d) nucleotides

Ans. The correct answer here is option (a) nucleoside.

Q3. Nucleic acids  are a polymer of nucleotide monomeric units. What does Each nucleotide consists of 

a) (base¬-sugar¬-phosphate)x

b) sugar-phosphate

c) base-sugar-phosphate

d) base¬-sugar-¬OH (base-sugar-phosphate)x

Ans. Here, the correct answer is  (c) base¬-sugar-¬phosphate.

Q4. How many nucleotides are present in the segment if DNA segment contains 100 Adenine and 100 cytosines ? 

a) 200

b) 100

c) 400

d) 500.

Ans. The correct option is ‘c’ 400.

Q5. Nucleoside contains

a) base-sugar

b) base-sugar-phosphate

c) base-phosphate  

d) sugar-phosphate

Ans. The correct option is (a) base sugar.

Q6. ATP is a

a) vitamin

b) nucleotide

c) nucleoside 

d) nucleic acid

Ans. Here, the correct answer is (b) nucleotides.

Q7. Where is the location of A phosphodiester bond :

a) Fatty acids in a diglyceride

b) Amino acids in a polypeptide

c) Monosaccharides in a polysaccharide

d) Nucleic acids in a nucleotide

Ans. Here, the correct answer is (d) nucleic acids in a nucleotide.

Q8. Name the sugar molecule present in nucleotide :

a)  hexose

b) tetrose

c) pentose

d) triose

Ans. Here, the correct answer is (c) pentose.

Q9. Name the nucleotide which contains only ribose sugar and not deoxyribose?

a) Cytosine – pentose sugar-phosphate 

b) Uracil – pentose sugar-phosphate

c) Thymine – pentose sugar-phosphate

d)  Thymine – pentose sugar-phosphate 

Ans. Here, the correct answer is (b) uracil – pentose sugar-phosphate.

Q10. Purine base found in RNA is called 

a)  Uracil

b) Thymine

c) Guanine

d) Cytosine

Ans. Here, the correct answer is (c) guanine.

Q11. Which of the following are not the components of RNA?
a) Guanine
b) Cytosine
c) Thymine
d) Adenine

Ans. Here,  the correct answer is (c) thymine, because thymine is present in DNA but not in RNA.

Q12.Which of the following statements is true?

a) Sugar component of a nucleotide is deoxyribose.

b) a pentose sugar moiety is attached to nucleotides  through a glycosidic linkage

c) Ribose is the sugar component of a nucleotide 

d)  Sugar molecule of the nucleotide is in L-configuration

Ans. Here, the correct answer is option (b)a pentose sugar moiety is attached to nucleotides  through a glycosidic linkage.