DNA:
A. Encodes then information needed for making proteins within the cell
B. Directs RNA to make lipids that are needed by the cel
C. Produces carbohydrates

i don't know, but does anyone wanna be friends? i'm doing my homework at 1: 49 in the morning : /

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.

the answer is 100% density i've answered this question before and done the quiz myself.