Question

2.1.2 quiz: protein synthesis
question 2 of 10
which action must take place before transcription can begin?
a. mrna leaves the nucleus and enters the cytoplasm.
b. a ribosome attaches to a strand of mrna.
c. rna polymerase binds to a coding region of dna.
d. ribosomes use rna polymerase to make nucleic acids.

Explanation:

Transcription is the process of synthesizing RNA from a DNA template. RNA polymerase is the enzyme that catalyzes this process. For transcription to begin, RNA polymerase must first bind to the promoter region (a specific coding region) of the DNA. This binding initiates the unwinding of the DNA double - helix and the synthesis of the RNA strand.

• Option A: mRNA leaving the nucleus and entering the cytoplasm occurs after transcription (during the process of translation initiation in eukaryotes).
• Option B: A ribosome attaching to a strand of mRNA is part of the translation process (protein synthesis from mRNA), not transcription.
• Option D: Ribosomes are involved in translation (synthesizing proteins from mRNA) and do not use RNA polymerase to make nucleic acids. RNA polymerase is used in transcription (synthesis of RNA from DNA).

Answer:

C. RNA polymerase binds to a coding region of DNA.