Which of these is the best source of stem cells and minimizes the risk with cell transplantation

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

The smallest parts of these that retain their original properties are called

Are gametes exactly the same? explain why or why not?