Question

An actively transcribing ribosomal RNA gene has a ""Christmas tree"" structure when visualized by electron microscopy. What are the ""branches"" and what is the ""trunk""?

Answer 1

"Trunk" is the chromatin which is closely packed ribosomal-RNA transcripts while the branches constitute of this ribosomal-RNA transcripts and at the tip of it is a ‘terminal ball’. See attachment for clear understanding how it actually look like.