Final answer:
No, most eukaryotic genes are not cloned directly into the vector for expression in prokaryotes. There are significant differences in gene expression between prokaryotes and eukaryotes, including the location and timing of transcription and translation.
Step-by-step explanation:
No, it is not true that most eukaryotic genes are cloned directly into the vector for expression in prokaryotes. While it is generally easier to introduce recombinant DNA into prokaryotic cells than into eukaryotic cells, there are significant differences in gene expression between the two. In prokaryotes, transcription and translation occur almost simultaneously, whereas in eukaryotes, transcription occurs in the nucleus and is separate from translation that occurs in the cytoplasm. Additionally, prokaryotes use different promoters than eukaryotes for transcription.