When the his—salmonella strain used in the ames test is exposed to substance x, no his+ revertants are seen. if, however, rat liver supernatant is added to the cells along with substance x, revertants do occur. is substance x a potential carcinogen for human cells? explain.

The test, which is used to examine the tendency of generating mutagens by a chemical is termed as the Ames test. The procedure is primarily used in bacteria to see whether the given chemical results in mutations in the DNA of the organism being examined.  

The positive test demonstrates that the chemical is mutagenic and can function as a carcinogen, this is due to the fact that cancer is associated with the mutation. The performed experiment in the given case indicates that substance X is a potential carcinogen.  

As the rat liver supernatant exhibited the enzymes, which transformed the substance X into mutagen. This led to the origination of his + revertants. The human liver possesses identical enzymes, which process the substance and transforms them into other components. This can cause mutation in human cells and can result in cancer.