Final answer:
The mRNA is shorter than DNA due to processes like splicing which remove non-coding regions. Isolating mRNA allows for probing gene origins, quantifying specific mRNAs, and locating transcripts in cells. Historical experiments have demonstrated the role of mRNA in protein synthesis and heredity.
Step-by-step explanation:
The mRNA is considerably shorter than the corresponding DNA sequence due to several biological processes such as splicing, RNA editing, and the presence of non-coding regions within DNA. During RNA splicing, introns (non-coding regions) are removed and exons (coding regions) are joined to form the final mRNA transcript. In addition, only a specific portion of DNA that contains the necessary information to synthesize a protein is transcribed into mRNA, and other segments are left out. The purpose of isolating and studying the mRNA includes being able to probe for the genes from which they originated, quantitatively measure amounts of specific mRNAs, and identify and quantitate the mRNA to even locate the transcripts in the cells. Historically, groundbreaking experiments by Nirenberg and Matthaei, as well as Avery, MacLeod, and McCarty, helped to elucidate the role of mRNA in protein synthesis and genetic inheritance, respectively. Practically, when conducting experiments like purifying RNA via column purification and evaluating RNA purity using denaturing urea PAGE and determining RNA concentration using UV spectrometry, it is essential to isolate mRNA to ensure accurate scientific results.