explain two complexities that are observed in the process of transcription in eukaryotes and not in prokarytes

Transcription in eukaryotes is more complex than in prokaryotes due to several factors. Here are two key complexities unique to eukaryotes:

1. Chromatin Structure and Remodeling: In eukaryotes, DNA is packaged into chromatin, which consists of DNA wrapped around histone proteins. This packaging can inhibit access to the DNA for transcription. Eukaryotic transcription requires chromatin remodeling to make the DNA accessible. This involves the modification of histones (through acetylation, methylation, etc.) and the action of chromatin remodeling complexes that reposition or evict histones. Prokaryotes, in contrast, have a more accessible DNA structure as they lack this chromatin packaging.

2. Pre-mRNA Processing: Eukaryotic genes are initially transcribed into precursor mRNA (pre-mRNA), which undergoes extensive processing before becoming mature mRNA. This processing includes the addition of a 5' cap, splicing to remove introns, and the addition of a poly-A tail at the 3' end. These modifications are essential for mRNA stability, nuclear export, and translation. In prokaryotes, the mRNA is typically transcribed directly into its functional form without these extensive modifications, as prokaryotes lack introns and perform transcription and translation simultaneously in the same compartment.