Choose the correct answer to complete the thought. if the sperm gamete that fertilizes an egg has a(n) chromosome, it will form female offspring. a. x b. y c. xy d. xx

The deserts of the sahara and australia are associated with

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

What is thought to have caused the mass extinction at the end of the cretaceous period?