Which prevents the lac genes in the dna of e. coli from being expressed most of the time

The Lac repressor prevents the Lac genes in the DNA of E.coli from being expressed most of the time.

Hope this helps!

-Payshence

true, i don't really know what you're asking but from the info you provided im guessing the answer is true.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.