Transcription is the process by which genetic information encoded in DNA is copied into RNA. It is an essential step in gene expression and occurs in both prokaryotic and eukaryotic cells. However, there are several remarkable differences between transcription in these two types of cells.

1. Genetic material:
- In prokaryotic cells, transcription occurs in the cytoplasm since they lack a well-defined nucleus. The genetic material (DNA) is present in the form of a circular chromosome.
- In eukaryotic cells, transcription occurs in the nucleus. The genetic material (DNA) is organized into multiple linear chromosomes present within the nucleus.

2. Complexity:
- Prokaryotic transcription is a simpler process as there is a single RNA polymerase enzyme responsible for transcribing all types of genes.
- Eukaryotic transcription is more complex as there are multiple RNA polymerase enzymes (I, II, and III) that transcribe different types of genes.

3. RNA polymerase:
- In prokaryotes, a single RNA polymerase enzyme is responsible for both initiation and elongation of transcription.
- In eukaryotes, RNA polymerase II is responsible for the initiation and elongation of transcription, while RNA polymerases I and III are responsible for transcribing specific genes.

4. Promoter region:
- In prokaryotes, the promoter region is relatively simple and consists of a consensus sequence called the -10 and -35 regions, where RNA polymerase binds to initiate transcription.
- In eukaryotes, the promoter region is more complex and consists of several regulatory elements including TATA box, enhancers, and silencers, which are recognized by transcription factors to initiate transcription.

5. Post-transcriptional modifications:
- In prokaryotes, the newly synthesized RNA molecule does not undergo significant modifications and can be directly translated into protein.
- In eukaryotes, the newly synthesized RNA molecule undergoes several post-transcriptional modifications including capping, splicing, and polyadenylation, which are necessary for the stability and processing of mRNA before it can be translated into protein.

6. mRNA processing:
- In prokaryotes, there is no mRNA processing. The mRNA molecule is polycistronic, meaning it can encode multiple genes in a single transcript.
- In eukaryotes, mRNA processing occurs, including the removal of introns through splicing, resulting in a mature, monocistronic mRNA molecule.

In conclusion, transcription in prokaryotic and eukaryotic cells differs in terms of the location, complexity, RNA polymerases involved, promoter regions, post-transcriptional modifications, and mRNA processing. These differences reflect the higher complexity and regulation of gene expression in eukaryotic cells compared to prokaryotic cells.