Ned is designing an experiment to test which hand sanitizer kills the most e. coli bacteria. in order for ned's results to be valid, what must he do?

In trying to determine whether dna or protein is the genetic material, hershey and chase made use of which of the following facts? a) dna contains sulfur, whereas protein does not. b) dna contains phosphorus, whereas protein does not. c) dna contains nitrogen, whereas protein does not. d) dna contains purines, whereas protein includes pyrimidines.