Passive Transport: Simple Diffusion
Diffusion across a cell membrane is a type of passive transport, or transport across the cell membrane that does not require energy. Remember that the cell membrane is a phospholipid bilayer. Although the inside and the outside of a cell are both water-based, there is a hydrophobic region in the middle, and this is an important barrier to anything large, charged, or hydrophilic. Molecules that are hydrophobic, just like the hydrophobic region, can pass through the cell membrane by simple diffusion.
Therefore, simple diffusion is the unassisted passage of small, hydrophobic, nonpolar molecules from a higher concentration to a lower concentration. Very small molecules can slip through the cell membrane, too, even if they are hydrophilic - just like a few ants might crawl through a crack in the wall just because they're tiny.
Answer:
A bone marrow transplant may result in a very specific type of rejection called the <u>Graft-versus-host disease</u>
Explanation:
The Graft-versus-host disease is a complicated immune condition which arises after a transplantation procedure. This condition arises when the immune cells of the donor, present in the transplanted tissue or organ, does not recognize and thus rejects and attacks the host tissues of the recipient. Therefore, leading to <u>Graft-versus-host disease.</u>
This disease is a common side effect after an allogeneic bone marrow transplant.
Chemical, digestion mechanical, thinking
A.
Animal cells are very close to plant cells, but they have one key difference that separates them; the cell wall.
A cell wall is a thicker layer on the outside of the cell membrane. These are unique, and are <u>only found in plant cells.</u> Animal cells just have the cell membrane as their outer part. This enables them to change shape due to the membrane being very flexible.
Plant cells do not change, and only conform to their cell wall's shape. This enables them to grow up (literally) to help gather sunlight and enable photosynthesis.
