The answer is bacterial cell
The lac repressor prevents the lac genes in the DNA of E. coli from being expressed most of the time. The answer to your question is A. I hope this is the answer that you are looking for and it comes to your help.
Catalyst maybe ( lower activation energy).
If you are implying one these choices not needed for survival it would be parents only when you can survive on your own (I'm not that sure but I hope this helped the slightest but)
Answer:
it wouldn't work
Explanation:
In a heterozygous genotype the dominant allele completely masks the effect of the recessive allele in the organism's phenotype.
