Which is a tough and flexible layer that surrounds plant cells, as well as some algal and bacterial cells. (a) cell wall (b) centriole (c) nucleus (d) cell membrane

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 the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

During binary fission, what events must occur before the cell splits into two new cells?