Your science teacher has charged you and your partner with making a dichotomous key. He has given you this chart of organisms that are all FISH. What characteristic would be best for beginning your key choices?

A) size of fish
B) body shape
C) fins or no fins
D) number of fins

What is a photon? a. part of a ribosome b. a light particle c. a carbon dioxide molecule d. part of a chloroplast b. a light particle

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above

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.