Human growth hormone can be made by genetically modified bacteria.
Name the small, circular piece of DNA found in bacteria that is used as a vector in genetic engineering.
Name the two enzymes involved in inserting the human gene into this bacterial vector.
To produce large quantities of human growth hormone, the genetically modified bacteria are grown in an industrial fermenter.
Describe an investigation to find out how the pH\text{pH}pH of the growth medium affects the yield of human growth hormone produced by these bacteria.
Your answer should include experimental details and be written in full sentences and paragraphs.
