BIO-Chemistry MCQs

Biochemistry Questions and Answers – Nucleotides & Nucleic Acids Basics

This set of Biochemistry Multiple Choice Questions & Answers (MCQs) focuses on “Nucleotides & Nucleic Acids Basics”.

1) Identify the purine base of nucleic acids in the following.
a) Cytosine
b) Thymine
c) Uracil
d) Adenine

Answer: d

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

Answer: a

3) Which of the following statements is true?
a) Sugar component of a nucleotide is ribose
b) Sugar component of a nucleotide is deoxyribose
c) The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage
d) The sugar molecule of the nucleotide is in L-configuration

Answer: c

4) What is the composition of nucleoside?
a) a sugar + a phosphate
b) a base + a sugar
c) a base + a phosphate
d) a base + a sugar + phosphate

Answer: b

5) What is the composition of nucleotide?
a) a sugar + a phosphate
b) a base + a sugar
c) a base + a phosphate
d) a base + a sugar + phosphate

Answer: d

6) Group of adjacent nucleotides are joined by ____________
a) Phosphodiester bond
b) Peptide bond
c) Ionic bond
d) Covalent bond

Answer: a

7) The sugar molecule in a nucleotide is ____________
a) Pentose
b) Hexose
c) Tetrose
d) Triose

Answer: a

8) Which of the following is true about phosphodiester linkage?
a) 5’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
b) 3’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
c) 5’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
d) 3’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide

Answer: a

9) Which of the following is false about purine and pyrimidine bases?
a) They are hydrophobic and relatively insoluble in water at the near-neutral pH of the cell
b) At acidic or alkaline pH the bases become charged and their solubility in water increases
c) Purines have two rings in their structure, but pyrimidine bases have only one ring
d) At acidic or alkaline pH the bases become charged and their solubility in water decreases

Answer: d

10) Building blocks of nucleic acids are ____________
a) Nucleotides
b) Nucleosides
c) Amino acids
d) Histones

Answer: a

11) Identify the purine base of nucleic acids in the following.

a) Cytosine

b) Thymine

c) Uracil

d) Adenine

Answer: d

12) A nucleoside is composed of

a) a base + a sugar

b) a base + a sugar + phosphate.

c) a base + a phosphate.

d) none of these

Answer: a

13) Genetic mutation occurs in

a) Protein

b) RNA

c) DNA

d) Nucleus

Answer: c

14) DNA is present in

a) Nucleus only

b) Nucleus, mitochondria and ER

c) Nucleus, mitochondria and chloroplast

d) Nucleus, mitochondria and RER

Answer: c

15) Which protein is shared by five histone protein?

  1. They are acidic proteins with relatively large molecular weight
  2. They are multimeric proteins with high level of Arg and Lys
  3. They are fibrous proteins with high amount of alpha-helix
  4. They are globular protein with a positive charge

          Answer: d

         16) Which is a property of both viral genetic material and bacterial genetic material?

  1. Both can be double stranded ,circular DNA
  2. Both can be single stranded ,linear RNA
  3. Both can be compacted into inverted repeats
  4. Both can be compacted into plasmid

        Answer: a

        17) Which is a general property of nucleoside and nucleotides?

  1. Both contain a hemiacetal or hemiketal bond
  2. Both contain a  nitrogenous base that contain covalent H- bond
  3. Both contain a pentose in the form of a furanose
  4. Both contain at least one 5’ – phosphate group

         Answer: c

           18)  Which component is found in both guanosine and uridine?

  1. Both contain an aldohexose
  2. Both contain three hydroxyl groups
  3. Both contain a 1,9 – bond
  4. Both contain a pyranose

      Answer: b

           19) The 6th most abundant element on Earth?

  1. Nitrogen
  2. Oxygen
  3. Carbon
  4. Hydrogen

    Answer: c

        20) Carbon is present                                    percent in human body

  1. 19%
  2. 3%
  3. 18%
  4. 65%

  Answer: C

     21) Carbon is a                                     language word

  1. Latin
  2. Greek
  3. English
  4. None of these

 Answer: a

   22) Atomic number of Carbon is

  1. 5
  2. 6
  3. 7
  4. 9

Answer: 6

  23) In Organic Compound Carbon form                                     bonds

  1. 4
  2. 6
  3. 7
  4. 3

 Answer: a

 24) Peptide (linkages) bond is formed in                              

  1. Carbohydrates
  2. Lipids
  3. Protein
  4. Fats

 Answer: c

   25) Atomic mass of carbon is

  1. 1.008 amu
  2. 12.000 amu
  3. 14.75 amu
  4. None of these

 Answer: b

  26) Glucose is used for the production of                                       

  1. Energy
  2. Food
  3. Metabolites
  4. Body process

  Answer: a

  27) Functional group generally determine the                             organic compound

  1. Nature and function
  2. Property
  3. Backbone
  4. All of these

   Answer: a

  28) Carbon formed the compound through the                                  bonding

  1. Hydrogen
  2. Covalent
  3. Metallic
  4. None of these

   Answer: b

 29) Which percentage of carbon dioxide inhaled in our body?

  1. 0.004%
  2. 0.002%
  3. 0.001%
  4. 0.005%

  Answer: a

    30) Carbon is a                                  compound

  1. Tri-valent
  2. Di –valent
  3. Tetra –valent
  4. Penta – valent

  Answer: c

   31) Carbon dioxide is a                                             gas

  1. Colorless
  2. Pink
  3. Yellow
  4. White

 Answer: a

  32) Plant use Carbon dioxide and sunlight to form

  1. Glucose
  2. Glycogen
  3. Water
  4. None of these

 Answer: a

  33) Carbo meaning                                 

  1. Gas
  2. Coal
  3. Both a and b
  4. None of these

  Answer: b                         

 34) Lab evidences suggested that atom in water molecule arranged in                                manner

  1. Non- linear
  2. Linear
  3. Bilinear
  4. None of these

  Answer: a

 35) Water is a                                                molecule

  1. Polar
  2. Non- polar
  3. Neutral
  4. None of these

  Answer: a

36) Nearly                                 carbon containing organic compound are known

  1. 10 million
  2. 20 million
  3. 30 million
  4. 50 million

  Answer: a

37) Living body is                                 of   H2O

  1. 40%
  2. 70%
  3. 50%
  4. 60%

  Answer: c

 38) Solid state of water has                                  more H-bond than liquid

  1. 15%
  2. 20%
  3. 40%
  4. 50%

Answer: a

39) Water is the best solvent due to its                                  nature

  1. Polar
  2. Non- polar
  3. Both a and b
  4. None of these

  Answer: a

 40) Energy Currency of the cell

  1. ATP
  2. GTP
  3. ADP
  4. None of these

  Answer: a

  41) Immunochemistry for determination of                                     tissues

  1. Muscle
  2. Pathological
  3. Both a and b
  4. None of these

  Answer: b

 42) Nutrient values of different food components detect only by

  1. Biochemical testing
  2. Blood testing
  3. Both a and b
  4. PCR

  Answer: a

 43) Scurvy disease is due to the deficiency of

  1. Vitamin –A
  2. Vitamin – C
  3. Vitamin – D
  4. None of these

  Answer: b

 44) Rickets disease is due to the deficiency of

  1. Vitamin – B
  2. Vitamin – C
  3. Vitamin – D
  4. Vitamin – E

   Answer: c

45) NIDDM cause by defect in                                        secretion

  1. Insulin
  2. Saliva
  3. Both a and b
  4. None of these

 Answer: a