The tryptophan operon found in E coli is a group of genes that encode the enzyme that E coli use for biosynthesis. The operon can be turned on and off. The operon is regulated and controlled by TRP Repressor. When bound to tryptophan, the trp repressor blocks the expression of the operon.
The tryptophan operon is a repressible operon meaning that it is active when there's less TRP available. Therefore, to control the TRP operon when tryptophan is available, the tryptophan molecule must bind to the TRP repressor.
The question that could be investigated through scientific research is B. Does a newly synthesized chemical reduce bacteria? The answer is B. Because the other questions aren’t science questions. They are bias.
Binary Fission basically means each bacteria splits into two. So after the first two hours, the 7 bacteria split into 14. After the next two hours, the 14 bacteria each split and the end result is 28 bacteria.