All compounds that have been found to be mutagenic in the Ames test are also carcinogenic. View Available Hint(s) All compounds that have been found to be mutagenic in the Ames test are also carcinogenic. True False Submit Part B Why are liver extracts used in the Ames test? View Available Hint(s) Why are liver extracts used in the Ames test? A liver extract is necessary for the bacteria to produce histidine revertants. Liver enzymes activate the bacterial enzymes. Liver enzymes may activate some innocuous compounds, making them mutagenic. The bacteria require the nutrients present in the liver extract for growth.