Which of the following are disadvantages of the aristotelian classification system?
i. the system contained too many groups to be useful.
ii. the system did not show relatedness of organisms.
iii. organisms were grouped by habitat, not structrual similarity.
iv. it was an expensive and highly technical process.

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.