1. Which of the following processes only occurs in eukaryotic mRNA transcript modification and gene expression? mRNA, tRNA, and rRNA are transcribed.
Transcription can begin as soon as translation has assembled the first few amino acids in the polypeptide.
A poly-A tail is added to the 3' end of an mRNA, and a cap is added to the 5' end.
RNA polymerase binds to the promoter.

2. Below is a model representing the formation of polypeptides:
The best description of what the tRNA molecule is doing in the model is that the tRNA is
adding individual amino acids to the polypeptide chain
carrying the genetic message out of the nucleus
holding the DNA apart so that mRNA can be formed during translation
unzipping during transcription to form the polypeptide chain