Skip to content

#Okazaki fragments

10 public questions tagged with this topic.

Which type of replication requires a break in the nucleotide strand to get started?

nucleic acid structure and recombination analysis shows hairpin formation, Holliday junction resolution and translation control ensure fidelity. Consequently Rolling circle replication emerges as the valid choice since it matches molecular mechanisms, aligning with established principles in molecular biology literature.

Ref: Watson et al., Molecular Biology of the Gene, 7th Edition, Chapter 9, Transcription and RNA Processing, describes RNA hairpin formation, secondary structures and regulatory mechanisms controlling gene expression.

Primers are synthesized where on the lagging strand?

This outcome reflects nucleic acid structure and recombination, where hairpin formation, Holliday junction resolution and translation control ensure fidelity. Option C captures this correctly because it matches molecular mechanisms, consistent with textbook descriptions and experimental observations in molecular biology.

Ref: Alberts et al., Molecular Biology of the Cell, 6th Edition, Chapter 5, DNA Replication and Repair, discusses Holliday junction formation during homologous recombination and replication fork dynamics ensuring genome duplication.

Discontinuous replication is a result of which property of DNA?

In molecular biology, nucleic acid structure and recombination dictates that hairpin formation, Holliday junction resolution and translation control ensure fidelity. Therefore Antiparallel nucleotide strands is correct as it matches molecular mechanisms, supported by mechanistic studies and conserved across related systems.

Ref: Alberts et al., Molecular Biology of the Cell, 6th Edition, Chapter 5, DNA Replication and Repair, discusses Holliday junction formation during homologous recombination and replication fork dynamics ensuring genome duplication.

Okazaki fragments are

This outcome reflects quantitative reasoning, where ratio, percentage and series logic determine correct calculation. Option D captures this correctly because it meets mathematical and logical criteria, consistent with textbook descriptions and experimental observations in aptitude and reasoning.

Ref: Wren and Martin, High School English Grammar and Composition, Revised Edition, Chapter 12, discusses vocabulary and comprehension providing guidance for verbal aptitude and logical inference assessment.

Joining of Okazaki fragments requires

Okazaki fragment synthesis inevitably leaves gaps between fragments after primer removal. Pol I synthesizes DNA to fill those short single-strand gaps using upstream 3' OH as primer ensuring precise replacement of RNA with DNA in 5' to 3' direction. Once filling complete, adjacent fragments remain connected by single phosphodiester nick because polymerase cannot create final bond between 3' hydroxyl and 5' phosphate. DNA ligase using NAD+ cofactor in bacteria hydrolyzes to close nick forming continuous phosphodiester backbone. Requirement for both enzymes couples gap filling and final ligation

Ref: Alberts et al., Molecular Biology of the Cell, 7th ed., Chapter 5: Joining Okazaki fragments by Pol I and DNA ligase

Okazaki fragments are formed on

Okazaki fragments, 1000 to 2000 nucleotides long in bacteria and 100 to 250 in eukaryotes, are short nascent DNA segments observed during brief pulse labeling experiments. They appear exclusively on lagging strand because its template synthesized opposite to fork movement. Each fragment begins with 10 to 12 nucleotide RNA primer made by primase that provides essential 3' OH for Pol III extension. Polymerase extends until reaching previous fragment then displaces or awaits processing. Leading strand shows no such fragments under normal physiological conditions.

Ref: Alberts et al., Molecular Biology of the Cell, 7th ed., Chapter 5: Okazaki fragments on lagging strand

Lagging strand synthesis is

Both template strands are antiparallel, but replication fork moves unidirectionally. Leading strand polymerase follows helicase smoothly synthesizing continuously. Lagging strand template runs 5' to 3' toward fork, requiring polymerase to synthesize away from fork advancement. As helicase unwinds parental duplex, new single-stranded DNA exposed discontinuously behind fork. Primase synthesizes short RNA primers at intervals, Pol III extends each into Okazaki fragment that later becomes processed and joined. This semi-discontinuous mode elegantly solves antiparallel constraint without violating

Ref: NCBI Bookshelf, Molecular Cell Biology, Lodish, Figure 11-21: Discontinuous synthesis of lagging strand