What part of the cell theory most implies that viruses, for all of their similarities to living cells, cannot be considered a life form according to definition?
a) all cells come from other cells.
b) all living things are made of one or more cells.
c) organisms do not arise by spontaneous generation.
d) cells are the basic units of structure and function in organisms.

B)All living things are made of one or more cells.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.

i would say it is