James was exposed to a pathogen when he was 10 years old and felt ill.

what would most likely happen if he were exposed to the same pathogen when he is 12 years old?

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

What was the land like over 500 million years ago? what was under the sea?

Contrast how pollination is different among gymnosperms and angiosperms.