DNA Structure and Replication

What are the components of a DNA nucleotide?

• Sugar, phosphate, nitrogenous base

• Amino acid, sugar, phosphate

• Nitrogenous base, amino acid, sugar

• Phosphate, lipid, nitrogenous base

Which enzyme is responsible for unwinding the DNA double helix during replication?

• DNA polymerase

• Helicase

• Ligase

• Topoisomerase

During DNA replication, what is the function of DNA polymerase?

• It seals the gaps between Okazaki fragments.

• It synthesizes new DNA strands from RNA primers.

• It adds nucleotides to the growing DNA strand in the 5' to 3' direction.

• It creates RNA primers.

Which of the following is not a nitrogenous base in DNA?

• Adenine

• Cytosine

• Uracil

• Thymine

What is the significance of the semi-conservative nature of DNA replication?

• Each daughter DNA molecule contains one strand from the parent and one new strand.

• Both strands of the daughter DNA molecules are newly synthesized.

• The parent DNA molecule is conserved while a completely new molecule is synthesized.

• Each base pair is conserved while the sugar-phosphate backbone is newly synthesized.

Which enzyme is responsible for joining Okazaki fragments together?

• DNA polymerase

• Helicase

• Ligase

• Primase

What is the role of primase during DNA replication?

• It synthesizes a short RNA primer to initiate DNA synthesis.

• It unwinds the DNA helix.

• It joins Okazaki fragments.

• It proofreads the newly synthesized DNA strand.

Which direction does DNA replication occur in?

• 3' to 5' only

• 5' to 3' only

• Both 3' to 5' and 5' to 3'

• Replication does not occur in a specific direction.

What is the shape of the DNA molecule?

• Single helix

• Double helix

• Triple helix

• Quadruple helix

Which describes the leading strand in DNA replication?

• It is synthesized continuously in the 5' to 3' direction.

• It is synthesized discontinuously in the 5' to 3' direction.

• It is synthesized continuously in the 3' to 5' direction.

• It is synthesized discontinuously in the 3' to 5' direction.