Which of the following genetically engineered organisms was used by Eli Lilly to prepare human insulin? 

The correct answer is Bacterium

Explanation:

• Human insulin, which is used to treat diabetes, is now commonly produced using genetic engineering techniques. This process involves inserting the human insulin gene into a suitable organism, which then produces insulin identical to that produced in the human body.
• Eli Lilly, a pharmaceutical company, was one of the pioneers in using genetically engineered organisms to manufacture human insulin. This marked a revolutionary advancement in biotechnology and medicine.
• The genetically engineered organism used for this purpose by Eli Lilly was the bacterium Escherichia coli (E. coli).
  • E. coli, a common bacterium, was genetically modified to produce human insulin. Scientists introduced the human insulin gene into E. coli cells using recombinant DNA technology.
  • The modified bacteria then synthesized insulin, which was harvested, purified, and used for medical purposes.
  • This method replaced the earlier practice of extracting insulin from the pancreases of pigs or cows, which had limitations such as allergic reactions and a limited supply.
  • Using bacteria like E. coli for insulin production is cost-effective, scalable, and ensures the production of insulin that is identical to human insulin.

Other Options:

• Yeast (Incorrect): While yeast cells, such as Saccharomyces cerevisiae, are also used in genetic engineering, they were not the organism initially used by Eli Lilly for insulin production. Yeast is sometimes used in modern biotechnology for producing proteins, but E. coli was the first organism used for this purpose in insulin production.
• Virus (Incorrect): Viruses are used in genetic engineering for purposes such as gene therapy or as vectors to deliver genetic material into cells. However, viruses are not suitable for producing large quantities of insulin due to their biology and replication mechanisms.
• Phage (Incorrect): Phages, or bacteriophages, are viruses that infect bacteria. They are often used in genetic research and as tools in biotechnology. They were not used by Eli Lilly for insulin production.