Name one way photosystem 2 and photosystem 1 are similar and one way they are different.

Both photosystems have multi-protein complexes with pigments, and an electron transport chain, in their thylakoid membranes reaction centers that harvest energy from light photons and used for photosynthesis. 

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.