MyCompetitiveExams Dynamic 180-question full-length simulator mixed dynamically from all 6 years for 2027 & 2026 aspirants.
The sequence that controls the copy number of the linked DNA in the vector, is termed:
The Origin of Replication (Ori) is the sequence from where replication begins. In cloning vectors, Ori is also responsible for CONTROLLING THE COPY NUMBER of the linked recombinant DNA! Selectable markers identify transformants; Recognition sites are for restriction enzymes. Mark Ori site (Option 2) in 5 seconds!
Ori is a specific sequence of DNA bases where DNA replication initiation proteins bind and initiate unwinding and bidirectional DNA synthesis.
NCERT states explicitly: "This sequence is also responsible for controlling the copy number of the linked DNA. So, if one wants to recover many copies of the target DNA it should be cloned in a vector whose origin support high copy number."
Selectable markers (like antibiotic resistance genes) allow identification and selective growth of transformants while eliminating non-transformants. Recognition/cloning sites are unique restriction enzyme target sequences. Palindromic sequences are the symmetrical nucleotide patterns recognized by restriction endonucleases.
Therefore, the sequence that controls the copy number of the linked DNA is specifically the Ori site.
Diagnose every choice: Know exactly why the right option works and why distractors fail.
Incorrect; selectable markers (e.g., ampicillin or tetracycline resistance genes) help in identifying and eliminating non-transformants, not controlling copy number.
Factually exact; the origin of replication (Ori) initiates replication and determines/controls the copy number of linked foreign DNA.
Incorrect; palindromic sequences are symmetrical recognition sites cleaved by restriction endonucleases.
Incorrect; recognition sites are points of cleavage where foreign genes are inserted, having no role in controlling copy number.
Ori = Initiates replication & CONTROLS COPY NUMBER. Selectable marker = IDENTIFIES TRANSFORMANTS. Cloning site = SINGLE RESTRICTION ENZYME SITE.
""
Test your speed and accuracy in the authentic 180-minute timed NTA simulator.
Spotted a mistake in this solution? Report an error ([email protected])
Cover all 1,140 official NEET questions in 285 days at your own pace. Progress is saved on your device. No login needed.