What is the best way to classify two different organisms that have similar appearance and are found in the same environment?

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? a) catalysis b) metabolism c) anabolism d) dehydration e) catabolism

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.