RNA is a molecule with characteristics and a role similar to DNA. Why is RNA necessary for DNA to fulfill its function?

What claim did thorne make? what evidence supported his claim?

Sexual reproduction in the parent cell will result in offspring with a) identical genetic information. b) half the genetic information. c) double the genetic information. d) four times the genetic information.

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.