Question

It helps in identifying and eliminating non-transformants

• A. Restriction enzyme
• B. Antibiotic
• C. Selectable marker
• D. Plasmid

Hint:

Selectable markers (e.g., antibiotic resistance genes) are essential for confirming successful transformation. When using ampicillin resistance as a marker, only the transformed cells will grow on ampicillin-containing media.

Answer 1

The Correct Option is C

Step 1: Define non-transformants.
Non-transformants are cells that have not taken up the foreign DNA during a transformation experiment. Step 2: Analyze the role of each option. (1) Restriction enzyme:
These cut DNA at specific sites but do not help identify transformed vs. non-transformed cells. (2) Antibiotic:
Antibiotics themselves are not used to identify cells. However, when linked to a resistance gene (marker), they allow for selection. (3) Selectable marker:
Correct answer. These genes (like antibiotic resistance genes) are inserted along with the gene of interest. When the cells are grown on antibiotic media, only transformed cells (with the marker) survive, helping in identification and elimination of non-transformants. (4) Plasmid:
Plasmids are vectors used to carry foreign genes but by themselves do not perform selection.