Pretty sure it's A (bacteria)
Answer:
Tricuspid valve is a structure present between right atrium and right ventricle. It is a one way valve composed of three flaps, hence the name. Blood flows from right atrium to right ventricle via it. It also prevents back flow of blood to atrium.
If a water filled right ventricle is squeezed, it will try to flow back into the right atrium. At this moment, the flaps of tricuspid valve will move upwards in horizontal position. As a result, the valve will close and water will not flow back to the right atrium.
Transport of a compound across a cell membrane (down a concentration gradient) was measured at several concentrations. The presence or absence of ATP had no effect on the transport of this compound. ... Why are the lipid bilayers in cells called "selectively permeable"? They are permeable to some substances but not others.
