Question

1. the single - stranded rna molecule that is transcribed in the nucleus and carries a coded message for translation on a ribosome is the

a. transfer rna (trna)
b. messenger rna (mrna)
c. ribosomal rna (rrna)
d. cytoplasmic rna (crna)

Explanation:

Messenger RNA (mRNA) is transcribed in the nucleus from DNA and carries the genetic code to the ribosome for protein - synthesis (translation). Transfer RNA (tRNA) brings amino acids to the ribosome, ribosomal RNA (rRNA) is part of the ribosome structure, and cytoplasmic RNA (cRNA) is not a standard RNA type in this context.

Answer:

B. messenger RNA (mRNA)