1. In terms of maximising diffusion, what was the most effective size cube that you tested?

In terms of maximum diffusion, the most effective size cube that was tested would be the smallest one (the 1cm x 1cm x 1cm cube).

2. Why was that size most effective at maximizing diffusion? What are the important factors that affect how materials diffuse into cells or tissues?

The reason the 1cm³ cube was the most effective at maximizing diffusion was because its surface area to volume ratio was the highest out of the 3, this happens because the larger surface area ratio to volume allows for diffusion to happen over the entire cube (or cell) while only having a smaller volume to actually “take over”/ diffuse and in this case it can be seen by the way the pink colour has spread throughout the different size cubes (see above). Important factors that affect how materials diffuse into cells or tissues are surface area (volume ratio will affect part of this.), concentration gradient, temperature, the permeability (of the cell membrane), these will all be needed to reach maximum diffusion efficiency.

3. If a large surface area is helpful to cells, why do cells not grow to be very large?

Although a large surface area is helpful to cells, cells do not grow to be very large because that means that the volume would also be larger and would have a larger area internally that would need to be diffused which means complete diffusion would take longer because of the ratio between the two, you want a high surface area to a small volume for a more efficient diffusion.

4. You have three cubes, A, B, and C. They have surface to volume ratios of 3:1, 5:2, and 4:1 respectively. Which of these cubes is going to be the most effective at maximizing diffusion, how do you know this?

Cube C will be the most effective at maximizing diffusion, it will be the most effective because its surface area to volume is the best ratio for efficient diffusion (high surface area to a low volume).

5. How does your body adapt surface area-to-volume ratios to help exchange gases?

As cells grow in size the surface area to volume ratio becomes less and less efficient for gas exchange to happen, and at some point the cell will grow to be too big for gas exchange to serve the internal needs of the cell, and when this occurs the cell either has to undergo mitosis or potentially lose function. Our bodies have adapted to having larger organs too by having them as spherical shapes which allow for maximum surface area exposure.

6. Why can’t certain cells, like bacteria, get to be the size of a small fish?

Certain cells can’t get to be the size of a small fish because it would be a bad surface area to volume ratio, and would lose its functional abilities, therefore it would have to undergo division to maintain their needed ratio. Bacteria are almost always single celled organisms which means they can only depend on their organelles within to survive, but that’s not the same with multicellular (next question).

7. What are the advantages of large organisms being multicellular?

Large organisms that are multicellular have specialized cells which are able to perform different functions (instead of a single cell that can only have one function). These multicellular organisms can function because the cells within are specialized for specific tasks, meaning the organism can grow and still be composed of the same cells because they arn’t effected by the surface area to volume ration because there are more of them composing this one thing.