Why do unicellular cells rely on diffusion?

Answer 1

Single cells are directly in contact with the surrounding environment, therefore a very short distance must be traveled in order for the oxygen to reach the mitochondria. Due to their small surface area, time for diffusion to occur is very short, therefore provision of oxygen, etc. is very fast, respiration may occur quickly.

In multicellular organisms, cells are not directly in contact with surrounding environment, therefore direct diffusion into each individual cell would take far too long, and for most cells is impossible. Therefore a transport system is needed to transport oxygen and glucose to the cells.

Answer 2

one celled organisms can obtain oxygen through the surface membrane of the cell. The rest of the cell uses the oxygen. The area of the cell's surface determines how much oxygen the organism can get(supply rate) and the volume of the cell determines how much oxygen the organism uses(demand rate). Ratio for supply to demand= Surface area over volume. Single celled organisms tend to have a higher surface are to volume ratio. This is because their surface membrane has a large enough area to supply all the oxygen the volume demands.

Answer 3

Unicellular cells rely on diffusion to obtain essential nutrients and eliminate waste products due to their small size and simple structure. Diffusion allows molecules to passively move across the cell membrane to maintain a balance of substances inside and outside the cell. This process is efficient for unicellular organisms as it does not require complex mechanisms or energy expenditure.

Answer 4

Without the movements of substances the nutrients wouldn't move to where the single- celled organisms need their nutrients.

Answer 5

Im from shawlands academy. Int 2 Biology and in 5th year. Ill tell you now, BIOLOGY SUCKS but still pick it. Im in mrs dickens class