Answer:
Promoter from the human insulin gene has large intron and limited tRNAs for complete expression
Step-by-step explanation:
A bacterial promoter sequence is used as it is made intron free which is not the case with human gene as it contains large introns. Hence an intron free version is created as cDNA. cDNA is made out of mRNA and has no regulatory region. Also, the bacterial promoter sequence contains sufficient ribosome-binding site, and terminator sequences with tRNAs in number enough for complete expression