Answer:
The heart valves
Explanation:
The heart valves prevent blood from flowing in the wrong direction in the heart. The valves are held in the proper place because of the chordae tendinae.
Explanation:
In simple diffusion, small molecules without charges such as oxygen and carbon dioxide flow through a plasma membrane without assistance and without expending energy. Other substances such as proteins, glucose and charged particles called ions cannot pass through the selectively permeable membrane
Basically when water goes over the earth it corrodes it and in that way shapes the earth's surface. The hydrosphere corrodes the gyoshere at Havasu Falls.
Answer:
Smaller single-celled organisms have a high surface area to volume ratio, which allows them to rely on oxygen and material diffusing into the cell (and wastes diffusing out) in order to survive. The higher the surface area to volume ratio they have, the more effective this process can be.
Explanation:
