Which structure of the heart acts like an automatic door that closes once blood enters a chamber and forces it to exit in the proper direction. a. atria c. arteries b. valves d. ventricles

Babies with very low or very high birth weight are less likely to survive. observe a graph of the data. % babies born at different weights % babies born in that category 6.0 6.5 in 50-555 70-75 80-8511 100-1055 which statement is a valid claim that could be made using the data in the graph? directional selection is occurring because the graph favors an extreme. mark this and retum save and exit next submit o type here to search