Which of the following is used in Genetic-Engineering?

Correct answer: (b) Plasmid

Explanation

A plasmid is a small, circular, extrachromosomal DNA molecule in bacteria that replicates independently of the chromosome.

Plasmids act as vectors in genetic engineering, carrying foreign genes into host cells.

Plastids, mitochondria and ribosomes are cell organelles, not gene-transfer tools.