Answer:
i dont know but you pfp bad ;/
Explanation:
Answer:
Oral poliovirus vaccine or Sabin vaccine, named for its inventor American physician and microbiologist Albert Sabin, was developed. OPV contains live attenuated (weakened) virus and is given orally.
The correct answer is A. Lac repressor.
Lac repressor prevents lac gene which are found in the DNA of Escherichia Coli from being expressed for many times.
Lac repressor is termed as DNA which binds proteins. It allows the expression of genes from coding which are made for proteins to be involved in metabolism of lactose which is in bacteria.
When there is no lactose which is available in the cell, then the genes are being repressed. Lactose are being converted to allolactose if they are available.