On a field expedition to Yellowstone National Park, you collected water samples from some of the hot springs in the hope of discovering new species of thermophilic bacterium. One such bacterium grew in the laboratory and after sequencing the entire genome of this new bacterium by the whole-genome shotgun approach, you use a computer program to search for start/stop signals for translation and homology searches based on similarity to cDNAs in the database. You predict approximately 20,000 genes. Is this an accurate representation of the total number of genes in the organism? Why or why not?

No, this is not an adequate representation for the total number of genes in the studied organism. The reason is because we are looking for start/stop signals to make comparisons with a database, and only genes that encode proteins carry start/stop signals; therefore, the 20,000 genes that were predicted correspond only to genes that encode proteins, leaving aside others that do not, so the estimate obtained is not correct.