Which of the following could be a nucleotide of dna?

Which two criteria must be met before scientist can use radiocarbon dating? explain your answer

Which of the following is a period in the paleozoic era? devonian cambrian permian all of the above

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods. c. it shows that these organisms share the same habitat. d. it provides evidence that these organisms suffered a genetic mutation.