Two experiments were performed. In the first one, Okazaki fragments were prepared from a replicating cell of E. coli grown in the presence of 32P. In the other,the two strands […]
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CSIR NET Life Science Previous Year Questions and Solution on DNA REPAIR AND RECOMBINATION
DNA Repair-Deficient Bacteria Produce More Antibiotic-Resistant Mutants, But Wild-Type Cells Also Generate Resistance
A bacterial culture initiated from a single bacterial cell with a DNA repair- deficient system is inoculated into several individual test tubes and allowed to grow in parallel. Wild type […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
Does Plasmid or Bacterial Genome Replicate Faster Using the Same Replication Machinery?
If bacterial genome and plasmid are allowed to replicate in same manner using same replication machinery then (1) Plasmid DNA will complete replication first (2) Bacterial DNA will complete replication […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPAIR AND RECOMBINATION
Key Features of the E. coli SOS Response: Role of RecA, LexA, and Translesion Polymerases
The following statements are made about the E.coli SOS response to DNA damage: A. RecA-DNA filament complex stimulates the autoproteolytic activity of the Lex A repressor. B. RecA is activated […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
How Multiple Origins of Replication Enable Rapid Mammalian DNA Replication Despite Slow Fork Speed
Speed of DNA replication in mammals is 256 bp/sec, so for replication of 3X109bp DNA it will take a very long time, but it is completed within few hours because […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPAIR AND RECOMBINATION
UV Exposure Is a Primary Inducer of the Bacterial SOS Response: Mechanisms and Implications
Which of the following can induce SOS response in bacteria (1) UV exposure (2) Hydroxyl-amine (3) 5-Fluro-Uracil (4) 2-Aminopurine Which Agents Induce the SOS Response in Bacteria? UV Exposure and […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
Understanding How E. coli Divides Every 20 Minutes While Genome Replication Takes 40 Minutes: The Role of Overlapping Replication Rounds
In E. coli grown under nutrient rich conditions, replication of entire genome takes about 40 min., yet it can divide every 20 min. This is so because: (1) While E. […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
How Uni-directional Replication Affects E. coli Genome Duplication Time Compared to Bi-directional Replication
E. coli takes 40 min. to duplicate its genome using a bi-directional mode of replication. If E. coli were to use uni-directional mode of replication to synthesize a full copy […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPAIR AND RECOMBINATION
Lesion Bypass Prevents Replication Fork Collapse Caused by UV-Induced DNA Damage
UB-induced DNA damage cause advancing replication forks to stall. To avoid a collapse of these stalled replication forks the cell uses: (1) non-homologous end joining (2) lesion bypasss (3) mismatch […]
CSIR NET Life Science Previous Year Questions and Solution on DNA REPLICATION
How to Calculate E. coli Generation Time with Overlapping DNA Replication Cycles
It takes 40 minutes for a typical E. coli cell to completely replicate its chromosome. Simultaneous to the ongoing replication, 20 minutes of a fresh round of replication is completed […]
