There are two bright stars in a constellation. One of the stars appears red and the other star appears blue. Which of the following is the best explanation for the difference in the stars' color? The blue star must be moving toward Earth and the red star away from Earth.

The red star must be moving toward Earth and the blue star away from Earth.

The red star must have a greater surface temperature compared to the blue star.

The blue star must have a greater surface temperature compared to the red star.

C

Explanation:

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.