Which model of DNA replication was supported by the experiments of Meselson and Stahl?

A. Conservative

B. Semi-conservative

C. Dispersive

D. Replicative

What is the role of DNA helicase during DNA replication?

A. Adding nucleotides to the growing strand

B. Forming phosphodiester bonds

C. Unwinding the double helix

D. Synthesizing RNA primers

Which enzyme is responsible for adding nucleotides to the growing DNA strand during replication?

A. DNA ligase

B. DNA polymerase

C. Primase

D. Topoisomerase

During DNA replication, which strand is synthesised continuously?

A. Lagging strand

B. Leading strand

C. Both strands are synthesised continuously

D. Neither strand is synthesised continuously

What is the function of primase in DNA replication?

A. Sealing nicks in the sugar-phosphate backbone

B. Synthesizing RNA primers

C. Removing RNA primers

D. Relieving supercoiling of the DNA

a) Explain the semiconservative model of DNA replication as proposed by Meselson and Stahl. How does this model ensure the accuracy of replication? [4]

b) Discuss the role and significance of DNA helicase and DNA polymerase in the process of DNA replication. [4]

a) Describe the initiation process of DNA replication, highlighting the role of the origins of replication. [3]

b) Explain the difference between the synthesis of the leading and lagging strands during the elongation phase of DNA replication. [4]

a) Discuss the significance of enzymes like primase and ligase in DNA replication. [3]

b) Explain how the termination of DNA replication occurs and why it is important for maintaining genomic integrity. [4]

a) Elaborate on the semiconservative nature of DNA replication, explaining how Meselson and Stahl demonstrated this model. [4]

b) Discuss the role of DNA helicase and primase during the initiation of DNA replication. [3]

c) How does the synthesis of the lagging strand differ from that of the leading strand, and why is DNA ligase important in this process? [4]

a) Describe the initiation of DNA replication, focusing on the role of the origins of replication and the enzymes involved. [4]

b) Explain the significance of the leading and lagging strands in the elongation phase of DNA replication. [3]

c) How does the termination phase of DNA replication contribute to the maintenance of genomic integrity? [4]

Which enzyme is responsible for joining Okazaki fragments on the lagging strand?

A. DNA helicase

B. DNA polymerase

C. DNA ligase

D. Primase

Where does the initiation of DNA replication occur?

A. Termination sites

B. Origins of replication

C. Centromeres

D. Telomeres

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

A. It ensures error-free replication

B. It allows for genetic variation

C. It preserves the original DNA sequence in one of the daughter strands

D. It accelerates the rate of replication

Which enzyme relieves the supercoiling of DNA ahead of the replication fork?

A. DNA helicase

B. DNA gyrase (topoisomerase)

C. DNA polymerase

D. Primase

What is the role of the lagging strand in DNA replication?

A. It is synthesised continuously towards the replication fork

B. It is synthesised discontinuously away from the replication fork

C. It acts as a template for the leading strand

D. It prevents the unwinding of the DNA helix

a) Explain how the semiconservative model of DNA replication preserves the genetic information of the cell. [3]

b) Discuss the roles of DNA polymerase and DNA ligase in the elongation and completion of the new DNA strands. [4]

c) Why is the accurate termination of DNA replication essential for the cell, and what could be the implications of errors in this process? [4]

a) Discuss how Meselson and Stahl’s experiment supported the semiconservative model of DNA replication. [4]

b) Describe the roles of primase and DNA polymerase during the elongation phase of DNA replication. [3]

c) Explain the importance of the termination phase in DNA replication and how it ensures the stability of the genome. [4]

a) Describe the semiconservative model of DNA replication and explain how Meselson and Stahl’s experiment supported this model. [4]

b) Discuss the role of DNA helicase in the initiation of DNA replication and why it is crucial for the unwinding of the DNA double helix. [3]

c) During the elongation phase of DNA replication, how does the synthesis of the lagging strand differ from the leading strand, and what role does DNA ligase play in this process? [4]

d) Explain the significance of the termination phase in DNA replication and how errors during this phase can impact the organism. [4]

a) Elaborate on how the semiconservative nature of DNA replication is essential for the preservation of genetic information across generations. [4]

b) Describe the roles of primase and DNA polymerase in the elongation phase of DNA replication and explain their significance. [4]

c) How does the synthesis of the lagging strand ensure the accuracy of DNA replication, and what role do Okazaki fragments play in this process? [3]

d) Discuss the implications of errors during the termination phase of DNA replication for cellular function and genomic integrity. [4]

a) Explain how Meselson and Stahl’s experiment demonstrated the semiconservative model of DNA replication and why this model is fundamental for genetic continuity. [4]

b) Discuss the initiation of DNA replication, focusing on the role of the origins of replication and the enzymes involved in unwinding the DNA. [4]

c) Describe the differences in the synthesis of the leading and lagging strands and explain the significance of DNA ligase in the elongation phase. [3]

d) What are the potential consequences of inaccuracies during the termination phase of DNA replication on the organism’s phenotype? [4]