The heart is a muscular organ that pumps blood. blood that contains waste materials is brought to the heart by blood vessels. this blood enters the and then moves down. the presence of prevents the backflow of blood inside the heart

ANSWER:

This blood enters the Right atrium, right ventricle and then moves down. The presence of the valves  prevents the backflow of blood inside the heart.

EXPLANATION:

regents of the university of california v. bakke, 438 u.s. 265 (1978), was a landmark decision by the supreme court of the united states. it upheld affirmative action, allowing race to be one of several factors in college admission policy.