In genetic engineering, the antibiotics are used
- As sequences from where replication starts
- As selectable markers
- To keep the cultures free of infection
- To select healthy vectors
Answer
(2) As selectable markers
Solution
As per NCERT, genes encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline or kanamycin are useful selectable markers for E. coli.
⇒ On a medium containing the antibiotic, only transformants (cells carrying the vector) survive, and non-transformants are eliminated.
Answer: (2)