Question

Operons ___________________________.

(a) are commonly found in eucaryotic cells
(b) are transcribed by RNA polymerase II
(c) contain a cluster of genes transcribed as a single mRNA
(d) can only be regulated by gene activator proteins
(e) none of the above

Answer 1

Operons contain a cluster of genes transcribed as a single mRNA, characteristic of prokaryotic cells such as bacteria, featuring a promoter and an operator for gene regulation.

Step-by-step explanation:

Operons contain a cluster of genes transcribed as a single mRNA. They are a feature typical of prokaryotic cells, such as bacteria and archaea, and are essential for the efficient regulation of gene expression. Operons include a promoter, an operator, and often several genes that are transcribed together. The LAC operon and the trp operon are well-known examples that illustrate the inducible and repressible control mechanisms, respectively. In eukaryotic cells, however, gene regulation is generally more complex and typically does not involve operons, relying instead on enhancers and other regulatory sequences that can be quite distant from the genes they regulate.