Mutations in the nucleotide sequence of DNA are the ultimate source of genetic variation, which in turn results in genotypic and phenotypic variation in a population. Look at this population of rabbits. How many different genotypes and phenotypes do you observe

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.