Recombinant insulin avoids animal-derived risks

Steps:

• Identify the type: This refers to human insulin produced via recombinant DNA technology in bacteria or yeast, mimicking the human protein exactly.
• Compare to alternatives: Traditional insulin came from animal pancreases (pigs, cows), which could cause immune reactions.
• Evaluate advantages: Recombinant method produces pure human insulin, reducing side effects like allergies or impurities.
• Match to choices: Select the option highlighting elimination of animal insulin issues.

Why D is correct:

• Recombinant insulin is identical to human insulin, eliminating side effects from animal proteins due to antigenic differences, as per immunology principles of foreign protein rejection.

Why the others are wrong:

• A: Genetic therapy doesn't alter patient's germline DNA, so offspring aren't protected.
• B: This production method supplies external insulin; it doesn't repair or stimulate the patient's pancreas.
• C: The insulin gene is inserted into host cells (e.g., bacteria) for production, not into the patient's DNA.

Final answer: D