The part of a seed that stores food for the seedling to use as it grow is

the part of seed that stores food for seedling is

cotyledon .

it gives nourishment to seedling until it is able to produce it's own food by 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.