During meiosis, homologous chromosomes line up next to each other. In some cases, one arm of a chromatid crosses over the arm of another chromatid. What is the result of this process?

A. Additional sex cells are created.
B. There is variation in the DNA of each sex cell.
C. There is a fully copied set of DNA in the offspring.
D. There is independent assortment of genetic material.

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.