Molecular Structure of DNA

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What is the distance between the nitrogenous bases in the DNA molecule?

3.4 nm
1 nm
0.34 nm (correct)
10 nm

What is the process of copying DNA before cell division?

Translation
Replication (correct)
Transcription
Mutation

Who deduced the structure of DNA through observations of X-ray crystallographic images?

Darwin
Crick
Watson (correct)
Franklin

What is the nature of the sugar-phosphate backbones in the DNA molecule?

Antiparallel (D) Signup and view all the answers

What is the type of replication that occurs in DNA, where each new molecule is composed of one parent strand and one new strand?

Semiconservative (D) Signup and view all the answers

What is the pairing of nitrogenous bases in the DNA molecule?

Adenine with Thymine, and Cytosine with Guanine (C) Signup and view all the answers

What is the function of primase during DNA replication?

To join RNA nucleotides into a primer (C) Signup and view all the answers

What is the role of DNA polymerase III during lagging strand synthesis?

To add DNA nucleotides to the primer, forming an Okazaki fragment (D) Signup and view all the answers

What is the primary function of topoisomerase in DNA replication?

To prevent supercoiling during unwinding (B) Signup and view all the answers

What is the function of DNA ligase during DNA replication?

To form a bond between the newest DNA and the adjacent DNA (D) Signup and view all the answers

In which direction is the leading strand synthesized?

5' - 3' (B) Signup and view all the answers

What is the direction of DNA replication?

From 5' to 3' on both the leading and lagging strands (C) Signup and view all the answers

What is the role of primase in lagging strand synthesis?

To synthesize RNA primers (B) Signup and view all the answers

What is the function of single-strand binding proteins during DNA replication?

To coat the DNA around the replication fork to prevent rewinding (D) Signup and view all the answers

What is the enzyme responsible for replacing RNA primers with DNA nucleotides on the lagging strand?

DNA polymerase I (A) Signup and view all the answers

What happens to the RNA primer on the third fragment after DNA polymerase III reaches it?

It is replaced with DNA nucleotides by DNA polymerase III (D) Signup and view all the answers

What is the role of DNA ligase in lagging strand synthesis?

To bond the 3' end of one fragment to the 5' end of another (D) Signup and view all the answers

What is the direction of synthesis of the Okazaki fragments on the lagging strand?

Discontinuous and in the 5'-3' direction (C) Signup and view all the answers

What would be affected by mutations in the enzyme DNA polymerase I?

lagging strand (B) Signup and view all the answers

Mutations in the enzyme primase would affect the synthesis of which new strand?

lagging strand (D) Signup and view all the answers

What is the role of helicase in DNA replication?

To unwind the parental double helix (A) Signup and view all the answers

What would be affected by mutations in the enzyme DNA ligase?

lagging strand (B) Signup and view all the answers

What direction is the leading strand synthesized in?

5' 3' direction (C) Signup and view all the answers

Which enzyme is involved in the repair of Okazaki fragments on the lagging strand?

DNA polymerase I (B) Signup and view all the answers

What is the role of primase in DNA replication?

To begin synthesis of RNA primer (B) Signup and view all the answers

During bacterial replication, which strand has continuous synthesis?

leading strand (B) Signup and view all the answers

What happens when DNA pol III reaches the RNA primer on the third fragment?

It dissociates and moves to the replication fork (D) Signup and view all the answers

What is the role of DNA ligase in DNA replication?

To bond the 3' end of the second fragment to the 5' end of the first fragment (C) Signup and view all the answers

What is the final step in the synthesis of the lagging strand?

The replacement of the last RNA nucleotide with DNA (C) Signup and view all the answers