The study of e. coli led scientists to new experimental designs for studying operons. how did scientists begin studying operons? they began to study cell division of cells under a microscope to determine how operons worked. they began testing different chemicals on e. coli to determine the number of operons present. they began reading the genome sequence of organisms to determine the number and organization of operons.

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.