Answer:
because the ovum is made to fertilize only a sperm at a time, once a sperm enters it closes. It then divides to form twins, triplets and so on
In mammals urine is expelled through the urethra which is part of the excretory system in unicellular organisms waste products are discharged directly through the surface of the cell
Yes indeed that the picture shows that the transport of the sodium and potassium ions. The picture shows a passive transport of sodium and potassium ions. And also we can see that the energy for the action of the pump is being released by the utilization of the ATP. Some are being moved and some are being brought back in.