What creates cDNA for use in laboratory studies?

The creation of complementary DNA (cDNA) for laboratory studies involves the process of reverse transcription from messenger RNA (mRNA). During this process, an enzyme called reverse transcriptase synthesizes a strand of DNA complementary to the RNA template. This is particularly useful in research contexts, as cDNA allows scientists to analyze gene expression, study the functions of specific genes, and produce recombinant proteins.

The advantage of cDNA is that it is derived from mRNA, which represents only the expressed genes in a particular cell or tissue type. This focused approach enables researchers to study the active portion of the genome, filtering out the non-coding regions that do not contribute to the protein-coding activity at the time of analysis.

In contrast, other processes mentioned involve different mechanisms of nucleic acid synthesis or conversion. For example, RNA polymerase processes involve the synthesis of RNA from DNA templates but do not create cDNA directly. Transcription from genomic DNA produces RNA, while translation is the process of synthesizing proteins from mRNA, not cDNA. Thus, reverse transcription is specifically the method that produces cDNA for use in laboratory studies, making it the correct choice in this context.