Final answer:
Comparing the entire genome of pathogenic and nonpathogenic bacteria can help identify genes associated with disease-causing abilities. By analyzing the genetic differences between these bacteria, researchers can pinpoint specific genes that contribute to pathogenicity.
Step-by-step explanation:
Comparing the entire genome of pathogenic and nonpathogenic bacteria can help identify genes associated with disease-causing abilities. By analyzing the genetic differences between these bacteria, researchers can pinpoint specific genes that contribute to pathogenicity, such as those involved in the production of toxins or the evasion of immune responses.
For example, the genome of Bacillus anthracis, the bacterium that causes anthrax, was compared to that of a related but less pathogenic bacterium, Bacillus cereus. Researchers found that certain virulence factors, like toxin-encoding plasmids, were present in B. anthracis but not in B. cereus. This comparison helped identify specific genes associated with the highly virulent nature of B. anthracis.
Therefore, by examining the differences in the genomes of pathogenic and nonpathogenic bacteria, scientists can uncover the genetic basis for disease-causing abilities.