Which of the following describes an example of an energy resource that does not pollute the air with greenhouse gases?
a)wind power, which converts wind to electrical energy
b)natural gas, which is released and used from sedimentary rock deposits
c)fossil fuels, which transform the energy of flowing water into useable electricity
d)biomass energy which is generated by burning wood or garbage

The hershey and chase experiments involved the preparation of two different types of radioactively labeled phage. which of the following best explains why two preparations were required? a. the bacteriophage used in the experiments was a t2 phage. b. it was necessary that each of the two phage components, dna and protein, be identifiable upon recovery at the end of the experiment. c. each scientist had his own method for labeling phage, so each conducted the same experiment using a different isotope. d. establishing the identity of the genetic material required observation of two phage generations.