In what part of the cell does cellular respiration occur

hi~~

i would say that hybridization occurs frequently in nature, because there are many types of hybrids that have occurred naturally, such as the mule (male donkey + female horse)

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.