They are the offspring of these two people They are the grandchildren of these two people Every organism exhibits one or more of the traits of their grandparents. Traits are passed by genes on the DNA Every organism exhibits one or more of the traits of their grandparents. Your description could involve; via the people who married into the family, by the expression of a recessive trait, via mutation. The children share more traits with parents than the grandchildren share. The children share more DNA with their parents than the grandchildren share From their parents Humerous---------------------------------Ulna------- -------Radius -------Metacarpals Ulna-------------Radius Ulna------- Ulna------- -------Radius -------Radius -------Metacarpals ----Phalanges -------Metacarpals------- ----Phalanges ---Phalanges---- Grasping, hanging, holding, walking, running, flying, swimming Similar order (humerous to phalanges). exact same number of humerous, radius, and Ulna bones. Ulna and radius are always side by side. The blueprint is found in the genes on chromosomes They share a common ancestor like grandchildren in families are ancesters of grandparents. Because the length and number of bones is similar in humans and dogs, they must share the most common amount of DNA sequences. A is most closely related to B because they share the greatest % of DNA similarity. A and D are least related. Only 50% of their DNA is similar. A and D share a recent common ancestor because they have the most similar DNA You could do a DNA comparison analysis of X with A through D. This would indicate with which of organisms A-D it is most closely related and should be classified similarly. Answers will vary. See Mr. Nelson to discuss.