O Levels Biology (5090)•5090/12/M/J/22
Explanation
Sequence of recombinant insulin production Steps:
- Extract human insulin gene from human cells (2) to isolate the required DNA.
- Insert the gene into bacterial DNA (4) via recombinant DNA technology.
- Allow modified bacteria to reproduce (3) in culture to increase population.
- Harvest insulin produced by bacteria (1) and scale to commercial levels (5).
Why D is correct:
- D (2→4→3→1→5) matches the standard biotechnology protocol for genetic engineering, where gene isolation precedes vector insertion, cell multiplication, expression, and mass production.
Why the others are wrong:
- A: Begins with bacterial reproduction before gene extraction or insertion, omitting commercial scale.
- B: Repeats gene insertion illogically and places extraction after production.
- C: Places gene extraction after insertion and commercial production before reproduction and expression.
Final answer: D
Topic: Genetic modification
Practice more O Levels Biology (5090) questions on mMCQ.me