Question

a research lab at ufv has purified the mrna that codes for a mouse protein called abc. the mrna was reverse transcribed (using reverse transcriptase) into cdna. they then used the cdna as a probe to locate the gene on the mouse chromosome, which they isolated and cloned. to their surprise, the coding region of the abc gene (on the mouse chromosome) was 5500 bases longer thanthat of the cdna. how would you explain the difference in size between the cdna and genomic forms of the abc gene?

Answer 1

The difference in size between the cDNA and the genomic forms of the abc gene is due to the presence of introns in the genomic DNA.

Step-by-step explanation:

The difference in size between the cDNA and the genomic forms of the abc gene can be explained by the presence of introns in the genomic DNA. Introns are non-coding regions of DNA that are transcribed into mRNA but are removed during the process of mRNA splicing. The cDNA is synthesized from the processed mRNA that has already had the introns removed. Therefore, the genomic DNA contains both coding and non-coding regions, whereas the cDNA only contains the coding regions of the gene.