Question

If a recombinant DNA bearing gene for resistance to antibiotic ampicillin is transferred to E.coli cells, the host cells become transformed into ampicillin resistant cells. If such bacteria are transferred on agar plates containing ampicillin, only transformants will grown and the untransformed recipient cells will die. The ampicillin resistant gene in this case is called as
A. selectable marker
B. recombinant protein
C. cloning site
D. chemical scalpels

Answer 1

Correct Answer - A
The cloning vector requires the presence of a selectable market, which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants and selectively permitting the growth of the transformants. Normally, the geneus encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline or kanamycin, etc. are considered useful selectable markers for E. coil. the normal E.coli cells do not carry resistance aganist any of these antibiotics.