IB Biology HL

What does a nucleosome consist of ?

• DNA and histones

• DNA and chromatin

• Chromatin and nucleotides

• Mature RNA and histones

To which parts of the deoxyribose molecule do phosphates bind in DNA?

• I and V

• III and IV

• II and III

• III and V

Tags

NGSS.HS-LS1-1

The drawing below shows a short section of a DNA molecule.

What is labelled by I, II and III?

• A

• B

• C

• D

Tags

NGSS.HS-LS1-1

What are pyrimidines in DNA?

• Types of nucleotides

• Types of base pairs

• Types of sugars

• Types of bases

What are Okazaki fragments?

• Sections of RNA removed by DNA polymerase III and replaced with DNA

• Nucleotides added by DNA polymerase I in the same direction as the replication fork

• Short sections of DNA formed during DNA replication

• Short lengths of RNA primase attached to the DNA during replication

What is the reason for Okazaki fragments being formed during DNA replication?

• To enable replication of the 3′ → 5′ (lagging) strand

• To form the template for the RNA primers

• To initiate replication on the 5′ → 3′ (leading) strand

• To help the DNA helicase unwinding the DNA helix

What happens during the formation of Okazaki fragments?

• DNA polymerase I adds nucleotides in the 5´ → 3´ direction.

• RNA polymerase adds nucleotides in the 3´ → 5´ direction.

• DNA polymerase III adds nucleotides in the 5´ → 3´ direction.

• DNA polymerase III adds nucleotides in the 3´ → 5´ direction.

The diagram below shows part of a DNA molecule that is being replicated.

Where would DNA polymerase link the next nucleotide during replication?

• I

• II

• III

• IV

Which enzyme removes the RNA primer during replication?

• RNA primase

• DNA polymerase I

• DNA helicase

• DNA polymerase III

What is the function of DNA polymerase I?

• To add appropriate nucleotides in the 3′ --> 5′ direction

• To remove the RNA primers and replace them with DNA

• To join together the Okazaki fragments

• To join together both strands of DNA to the histones