Question

A gene whose expression helps to identify transformed cell is known as

• A. Regulatory gene
• B. Housekeeping gene
• C. Structural gene
• D. Selectable marker

Hint:

• Selectable marker → Identifies transformed cells
• Example: Antibiotic resistance gene

Answer 1

The Correct Option is D

Concept: In genetic engineering, certain genes are used to identify whether a cell has been successfully transformed.
• Selectable markers allow identification of transformed cells.
• They often provide resistance to antibiotics or other selectable traits.

Step 1: Analyzing each option.

• Regulatory gene: Controls expression of other genes → Not used for identification.
• Housekeeping gene: Expressed in all cells for basic functions → Not a marker.
• Structural gene: Codes for proteins → Not used for selection.
• Selectable marker: Helps identify transformed cells (e.g., antibiotic resistance) → Correct.

Step 2: Selecting the correct answer.
Thus, the gene used to identify transformed cells is a selectable marker.