How does a stimulant, such as an amphetamine affect attention? Select one:
a. They impair attention at all levels,
b. At low levels, they increase attention. At high levels, they impair it,
c. They increase attention at all level,
O d. At low levels, they impair attention. At high levels, they increase it

4. discuss additional factors that some planets have that affect their seasons. 5. what fact about other planet’s seasons most surprised you and what did you find the most interesting? why?

Because of its structure the cell membrane is known as a phospholipid ? a.bilayer b.molecule c.fluid d.barrier

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