DNA Structure and Replication Practice Questions

Question 1

Which of the following molecular interactions are found in the structure of DNA?

Accepted Answer

All of the options

Answer

Hydrogen bond

Answer

Glycosidic bond

Answer

Covalent interactions

Question 2

Which enzyme polymerises Okazaki fragments?

Accepted Answer

DNA polymerase III

Answer

DNA polymerase I

Answer

DNA polymerase II

Answer

RNA polymerase

Question 3

Mutations are due to changes in:

Accepted Answer

DNA nucleotide sequence

Answer

RNA nucleotide sequence

Answer

Amino acid sequence of ribonuclease

Answer

Cell membrane

Question 4

Which of the following statements about gene therapy is false?

Accepted Answer

Gene therapy is only used for genetic disorders.

Answer

Gene also considered as drug

Answer

Gene therapy can be used to treat some cancers.

Answer

Has been tried in cystic fibrosis

Question 5

False statements are:

Accepted Answer

All of the options

Answer

DNA replication proceeds in one direction

Answer

Lagging strand is synthesized by RNA primase

Answer

Bacteria have multiple origins of replication

Question 6

Which of the following statements about Taq DNA polymerase is correct?

Accepted Answer

Optimum temperature for chain elongation is 75°C

Answer

Denatures at high temperatures

Answer

Provides high fidelity during DNA synthesis

Answer

Exhibits 3' to 5' exonuclease activity

Question 7

Which one of the following statements about chromatin is not true?

Accepted Answer

H2A-H2B bind to both the entry and exit ends of DNA in nucleosomes

Answer

DNA winds approximately 1.75 times around the nucleosomes

Answer

Covalent modification of histones influence chromatin compaction

Answer

Non-histone proteins are part of mitotic chromosomes

Question 8

Which type of bonds are represented by the dotted lines in the image? (AIIMS Nov 2017)

Accepted Answer

Hydrogen bond

Answer

Covalent bond

Answer

Ionic bond

Answer

Phosphodiester

Question 9

What is the most stabilizing force for nucleic acids?

Accepted Answer

Hydrogen bonds

Answer

Conformational entropy

Answer

Covalent bond

Answer

Van der Waals interaction

Question 10

What is meant by the melting of double-stranded DNA?

Accepted Answer

Splitting of double strands into single strands

Answer

Splitting of DNA into fragments

Answer

Formation of triple helix

Answer

Separation of double-stranded bases

DNA Structure and Replication — MCQs

DNA Structure and Replication — MCQs

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