NEW
Font size
WorksheetsIB Bio Dna Replication Sl
Total questions: 23
Worksheet time: 23mins
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
The drawing below shows a short section of a DNA molecule.
What is labelled by I, II and III?
A
B
C
D
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
The diagram below represents DNA replication. Some of the bases are indicated.
In which direction is the replication fork moving and which bases would be needed to replicate the section of DNA shown?
Direction = left to right; Bases = U, G and C
Direction = right to left; Bases = U, G and C
Direction = left to right; Bases = T, G and C
Direction = right to left; Bases = T, G and C
Where are free nucleotides added to a newly growing strand?
to the 5'OH group of the previous deoxyribose sugar
to the 5'OH group of the previous phosphate group
to the 3'OH group of the previous deoxyribose sugar
to the 3'OH group of the previous phosphate group
Which is true of the lagging strand during DNA replication?
DNA polymerase I adds nucleotides in a 5' --> 3' direction
DNA polymerase III adds nucleotides in a 5' --> 3' direction
DNA polymerase I adds nucleotides in a 3' --> 5' direction
DNA polymerase III adds nucleotides in a 3' --> 5' direction
What are Okazaki fragments made of?
DNA only
RNA only
DNA and RNA
Protein
Why does a lagging strand need to be made during DNA replication?
DNA polymerase I can only add nucleotides from 3' --> 5'
DNA polymerase I can only add nucleotides from 5' --> 3'
DNA polymerase III can only add nucleotides from 3' --> 5'
DNA polymerase III can only add nucleotides from 5' --> 3'
Which of the following is not true of the lagging strand during DNA replication?
It is made from 5' --> 3'
It is made in the same direction as the leading strand
It is made by stopping and starting again
RNA primers help it to be made
What keeps the DNA strands apart during DNA replication?
DNA gyrase
DNA helicase
DNA primase
single-stranded binding proteins
What is the role of RNA primers, which are needed to form the lagging strand?
To allow RNA polymerase to bind
To allow DNA polymerase to bind
To allow DNA primase to bind
To allow DNA ligase to bind
How does DNA replicate?
The deoxyribose of a free nucleotide is linked to the phosphate of the last nucleotide in the chain.
The phosphate of a free nucleotide is linked to the deoxyribose of the last nucleotide in the chain.
Nucleotides are linked in a 3′ to 5′ direction and the new strands are anti-parallel to the template strands.
Nucleotides are linked in a 5′ to 3′ direction and the new strands are parallel to the template strands.
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 are the fundamental packaging units of eukaryotic chromosomes?
Nucleosomes
Centromeres
Histones
Nucleoids
Which of the following is/are true of nucleosomes?
I. They contain six histone proteins
II. They control gene expression
III. They help in DNA supercoiling
I only
II only
II and III only
I, II and III
How is a new nucleotide added to a growing DNA strand?
The phosphate of the new nucleotide attaches to the 3'C of the previous nucleotide
The phosphate of the new nucleotide attaches to the 5'C of the previous nucleotide
The 3'C of the new nucleotide attaches to the phosphate of the previous nucleotide
The 5'C of the new nucleotide attaches to the phosphate of the previous nucleotide
