Which situation results in a characteristic that is
inheritable?
(1) a limb is lost when two marine organisms fight.
(2) a puppy learns to beg for food by watching
an older dog perform tricks.
(3) a gene is inserted into a bacterium, allowing
the organism to produce insulin.
(4) a random mutation causes the immediate
death of a microbe.

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.