What is the drug classification of nicotine?
a. stimulant and narcotic
b. depressant and diuretic
c. stimulant and depressant
d. narcotic and neuroleptic

Which of the following is not a main characteristic that scientists focus on when determining which kingdom an organism belongs to

About __ of the mass of the cell is water

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.