6) describe the events that must occur in order for sperm to penetrate an egg. what
prevents more than one sperm from entering? in the case of twins, how many sperm
entered the egg? why must a man have millions of sperm in a semen sample to be
considered fertile? if only one sperm were present in the semen and that sperm
managed to find its way to the egg, could it fertilize the egg? explain.
7) the period when blood is pushed into the arteries is called ________.
8) the adaption of the body to repeated exercise in hot environments occurs through a
process called ________.
9) if the stroke volume of the left ventricle is 65 ml/beat and the stroke volume of the
right ventricle is 68 ml/beat, what will happen to the relative distribution of blood in the
systemic and pulmonary circulation after 15 beats?