Question: 116. Which of the following genetically engineered organisms was used by Eli Lilly to prepare human insulin?
(1) Bacterium
(2) Yeast
(3) Virus
(4) Phage
Answer: Option (1)
Explanation:
The first commercial production of human insulin by Eli Lilly was achieved using genetically engineered bacteria.
The human insulin gene was inserted into a plasmid vector, which was then introduced into the bacterium Escherichia coli.
Inside the bacterial cells, the inserted human gene was expressed to produce insulin (initially as separate A and B chains, which were later combined).
Bacteria are preferred for this purpose because they grow rapidly, are easy to culture, and can be genetically manipulated efficiently.
Yeast was used later in other methods, but Eli Lilly specifically used bacteria for the first successful large-scale production of human insulin.
Hence, the correct answer is bacterium.