"You want to test the mutagenicity of a certain chemical that you suspect causes changes to DNA molecules. You have not been able to locate the Salmonella typhimurium strain that requires histidine in order to grow. What might you be able to use instead?"

Land conservation is a worldwide priority. there are several methods to prevent the loss of land due to a variety of reasons. which method is not a way to conserve land? a) sea walls b) rainwater harvesting c) limits on clear cuts of forests d) cut and burn methods of clearing land