Answer:
Explanation: In facilitated diffusion, molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels and carriers. A concentration gradient exists for these molecules, so they have the potential to diffuse into or out of, the cell by moving down it.
Answer:
B. Oxygen
Explanation:
Oxygen is a substance transported with the assistance of red blood cells
Answer: 26.75 meters.
2πr = 84
2 * 3.14 * radius = 84
radius = 84/6.28
r= 13.375
So the diameter will be 13.375 + 13.375 which is 26.75 meters.
Biodiesel (D) is made from vegetable oils and animal fats.