Question

where do the instructions for building a protein originally come from?
○ trna
○ dna
○ rrna
○ mrna

Explanation:

Genetic instructions for proteins start in DNA. DNA is transcribed into mRNA, which is then translated into protein. tRNA carries amino acids, rRNA forms ribosomes, and mRNA is a temporary copy—all trace back to DNA as the original source.

Answer:

B. DNA