The basic tool of genetic regulation is the ability of certain proteins to bind to specific

specific DNA elements

Explanation:

Gene regulation is a mechanism that acts to promote or repress the expression of a gene. It controls the rate and manner of gene expression. Gene regulation involves a complex set of interaction between genes, RNA molecules and proteins (transcription factors). A basic tool employed during gene regulation is the binding of proteins called transcription factors to specific DNA.

Transcription factors are proteins that play an important role in regulating the transcription of genes by binding to specific regulatory nucleotide sequences(DNA). Transcription factors (proteins) help turn specific genes on or off by binding to close DNA elements.

Transcription factors operate by either making it easy or hard for RNA polymerase (an enzyme that synthesizes new RNA molecule by attaching itself to DNA) to bind to the promoter of a gene. Transcription factors that boost gene transcription are called ACTIVATORS while those that inhibit gene transcription are called REPRESSORS.

b. heterotroph

explanation: