Which of the following is NOT a method of gene transfer?
Electrophoresis is used for DNA separation, not gene transfer. Microinjection, biolistics, and heat shock transformation are gene transfer methods. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Biology - Zoology portion covering relevant system and function, Topic: Structural organization and physiology.