What could be the possible harm of using antibiotic resistant gene as a selectable marker in plasmid, used for gene transfer in production of $GM$ food?

$(A)$ $GM$ food contains the enzyme produced by the antibiotic resistance gene that was used during gene tranfer in genetic engineering. This could cause allergies since it is a foreign protein.

$(B)$ The bacteria present in the alimentary canal of the humans could take up the antibiotic resistance gene present in $GM$ food.

$(C)$ The bacteria in the human alimentary canal would then become resistant to the concerned antibiotic.

$(D)$ The transgene may be transferred through pollen to their wild relatives and make weeds more persistant
and damaging.

How many recombinant therapeutics have been approved for human use in world over?

Biotechnology is the modern branch of biology which deals with

Technique used to detect $HIV$ in suspected $AIDS$ patient in asymptomatic stage is

Rennin used in cheese industry is