If events a and b are dependent, then a) a and b must occur together. b) a and b cannot occur together. c) a's occurrence can affect the probability of b's occurrence. d) a's occurrence cannot affect the probability of b's occurrence.

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.