The heart is to the as the brain is to the . A. respiratory system, excretory system

B. muscular system, circulatory system

C. respiratory system, muscular system

D. circulatory system, respiratory system

E. circulatory system, nervous system

F. muscular system, nervous system

Biology 1c cumulative exam i need awsners

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

When is your respiration rate likely to change? a. when your intestines are digesting b. when your cells have too much glucose c. when your cells need more oxygen d. when your liver is working after a meal