This question isn't really finished, but bacterium are unicellular prokaryote.
I hope this helps?.. :S
Transport proteins (carrier proteins and channel proteins) allow substances into and out of the cell that cannot pass through the phospholipid bilayer (as they’re either to large, charged or not lipid soluble) by facilitated diffusion.
Specifically channel proteins allow ions into and out of the cell by creating a pore in the membrane in which they can move through with their concentration gradient
Question:
how does a tumor form?
Answer:
En general, los tumores ocurren cuando las células se dividen y se multiplican excesivamente en el cuerpo. Normalmente, el cuerpo controla la división y el crecimiento de las células.
English:
In general, tumors occur when cells divide and multiply excessively in the body. Normally, the body controls the division and growth of cells.
Skeleton is what the connective tissue uses to stay part of the body. Without the skeletal system we wouldn't be able to move our muscles.