If earth rotated on an axis that was not tilted, how would this affect the seasons?

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above

What are 3 reasons that natural selection occurs

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.