Question

9 during protein synthesis, what does mrna do? a it delivers dnas instructions for making proteins to the ribosome b it constructs proteins out of random amino acids c it strings together two complementary rna strands d it strings together two complementary dna strands

Explanation:

To solve this, we analyze each option:

• Option A: mRNA (messenger RNA) is transcribed from DNA and carries the genetic code (instructions) from DNA in the nucleus to the ribosome (where protein synthesis occurs). This matches the role of mRNA.
• Option B: Ribosomes and tRNA (not mRNA) help assemble proteins from amino acids in a specific order (not random). So B is incorrect.
• Option C: mRNA is a single - stranded molecule. It doesn't string together two complementary RNA strands. That function is not associated with mRNA.
• Option D: mRNA is related to RNA, not DNA strand assembly. DNA replication and transcription have other molecules involved in DNA strand interactions. So D is incorrect.

Answer:

A. It delivers DNA's instructions for making proteins to the ribosome