Answer:
The correct answer is B. RNA polymerase finds and binds to the starting point of a gene.
Step-by-step explanation:
Transcription is the process by which the genetic information in DNA is copied into RNA. Before transcription can begin, the DNA molecule must be unwound and separated to expose the nucleotide sequence that will be transcribed. Once the DNA is exposed, RNA polymerase, an enzyme that catalyzes the formation of RNA, must find and bind to the starting point of a gene, which is typically marked by a specific DNA sequence called a promoter. Once the RNA polymerase is bound to the promoter, it begins to move along the DNA strand, synthesizing a complementary RNA molecule that is identical in sequence to one of the DNA strands. The resulting RNA molecule, called messenger RNA (mRNA), carries the genetic information from the DNA out of the nucleus and into the cytoplasm, where it is used to direct the synthesis of proteins. Option A is describing the process of translation, where tRNA molecules bring amino acids to a ribosome to assemble a protein from the mRNA template. Option C is an incorrect statement, as amino acids are not used by mRNA to produce DNA, rather, DNA is used as a template to produce mRNA. Option D is also incorrect, as rRNA attaches to the mRNA during translation, not transcription.