Which of the following is necessarily to be present in expression vector but not in cloning vector?
Cloning vector Expression vector DNA of interest is replicated and cloned into multiple copies. No transcription or translation happens with the cloning vector. The DNA of interest is expressed as RNA and proteins. The promoter is needed for transcription Shine-Dalgarno sequence (ribosomal entry site) is there to be recognized by ribosomal RNAs. eg: Synthesis of insulin All the other three components mentioned in question are present in both vector.
Origin of replication
Restriction site
Selectable marker
Ribosomal entry site
Techniques in molecular biology