Which type of substance cannot be separated physically

All organisms contribute some water to the water cycle by conducting

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?

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.