Which of the following is related to genetic engineering?

Correct option is B

The correct answer is (b) Plasmid

Explanation:
• A plasmid is a small, circular, double-stranded DNA molecule distinct from a cell's chromosomal DNA, commonly found in bacteria.
• They are fundamentally utilized as vectors in genetic engineering to carry and transfer foreign genetic material into target host cells to create recombinant DNA.

Information Booster:
• Plasmids naturally carry genes that offer favorable traits to bacteria, such as antibiotic resistance.
• By inserting desired human genes (like the gene for insulin) into a bacterial plasmid, scientists can rapidly produce mass quantities of medical proteins.

Additional Knowledge:
Plastid (Option a)
• Plastids are naturally occurring cellular organelles found primarily in plant cells (e.g., chloroplasts) responsible for photosynthesis and storage, not vectors.
Heterosis (Option c)
• Also termed hybrid vigor, this is a biological phenomenon where crossbred offspring exhibit superior traits compared to their parents; achieved by traditional breeding, not direct genetic engineering.
Mutation (Option d)
• A spontaneous or induced alteration in DNA sequencing. While harnessed in biotechnology, a plasmid is a physical tool central to recombinant methods.
None of the above/More than one of the above (Option e)
• Incorrect, as plasmids are definitively synonymous with foundational genetic engineering.

So the correct answer is (b)