How do single celled organisms obtain water from their external environment?

Easy!!

diffusion.. because single celled organisms have a large surface area to volume ratio meaning that there exchange surface is large enough to allow efficient diffusion fast enough to keep the cells alive (1 cell.. lol ). they also aren't very active they can rely on diffusion alone to take up water and other important solutes..

Diffusion through osmosis occurs in single celled organisms when they have a lower water potential inside the cell than outside so water flows into the cell (down the concentration gradient) via a partially permeable membrane.


hope that helped

from Kate Gibson
16