Which of the following is a protein essential for regulating gene expression? a. transcription factors b. operator genes c. promoter genes d. structural genes

The only correct answer would be transcription factors.

The question is a bit tricky: it's asking you for a protein that is essential - so only transcription factors fits this.

Oh, and operators are not genes (they are DNA sequences usually surrounding a promoter sequence)

Promoters are not genes (they are DNA sequences that signal to a mRNA polymerase to start transcription at that point on the DNA)

And structural genes are DNA...not proteins.

he movement of air through earth's or any planet's atmosphere is called wind, and the main cause of earth's winds is uneven heating by the sun. this uneven heating causes changes of atmospheric pressure, and winds blow from regions with high pressure to those with low pressure.

i hope this : )

it should be briana that has it to me