CBSE Class 12-science Answered

A marker gene is a gene used in molecular biology to determine if a nucleic acid sequence has been successfully inserted into the genetic material (DNA) of an organism. There are two types of marker genes: a selectable marker (such as antibiotic resistance gene) and a marker for screening (green fluorescent protein).

Antisense genes are constructed by reversing the orientation of a gene with regard to its promoter so that the antisense strand is transcribed into an antisense non-coding strand (ncRNA). They are used in genetic engineering to regulate the genetic expression of a trait.