A scientist is studying the action of RNA polymerase during transcription. He wants to know what type of bases are added to the growing mRNA by RNA polymerase.
A) bases complementary to the template DNA
B) bases the same as those in the template
C) bases similar to the template DNA @dumbsearch2

Question

A scientist is studying the action of RNA polymerase during transcription. He wants to know what type of bases are added to the growing mRNA by RNA polymerase.
A) bases complementary to the template DNA 
B) bases the same as those in the template
C) bases similar to the template DNA @dumbsearch2

dumbsearch2 · Answer

The answer is A. RNA polymerase will be making an mRNA using a single DNA strand as a template. So, for example if the DNA strand is AGGCAGC the mRNA strand will be UCCGUCG. 
U= uracil which replaces thymine in mRNA molecules. 

Hope this helps!