The human body cells have chromosomes.
a. 40, 20 pairs
b. 46, 23 pairs
c. 90, 45 pairs
d. 140, 70 pairs

Which plains area lies in both the united states and canada? altiplano central canadian shield coastal plains great plains

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

How do accessory pigments chlorophyll?