Which of the following correctly describes when plants began to colonize early earth?
a. after the dinosaurs went extinct
b. before prokaryotes first dominated the earth
c. directly before the age of reptiles
d. before eukaryotes grouped together to form multicellular organisms

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

The finches on the galapagos island were similar in form except for variations of their beaks. darwin observed that these variations were useful for: attracting a mate defending territory building nests gathering food

How did the discovery of the rhesus factor affect society? o more patients died from having a transfusion with the wrong rhesus factor 0 new treatments during pregnancy could prevent harm to the developing child. o less donated blood could be used in the treatment of patients. the number of blood types was reduced by half