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In terms of maximizing diffusion, the smallest cube was the most effective.

This cube was the most effective because it had the smallest volume.The smaller the volume of the cube, the solution is more capable of effectively penetrating into the middle of the cube, which allows for maximum diffusion. However, the larger the surface are, the more surface area exists for the solution to seep through. The larger the surface area to volume ratio, the more likely to diffuse at a maximum level it will be.

This suggests that the surface area of the cells must be very large, which would normally result in a large volume. However, a large volume means that more solution has to seep through the cell in order for the cell to be fully diffused. This would mean that a smaller volume would be more fitting for full diffusion. Regardless of the smaller surface area, the smaller volume allows for less solution to enter to be diffused, which allows for quicker diffusion as well.

Cube C will be most effective at maximizing diffusion because of the larger surface area to volume ratio. The high surface area number means that there is more “space” for the solution to enter the cube, and the low volume number means that there is less internal space within the cube for the solution to fully immerse in. We can see this with the bottom cube in the image, which has turned almost entirely pink as opposed to the top cube which still has a large portion in the center that did not turn pink.

In order for a cell to properly function, there must be a high surface area to volume ratio that allows adequate entering/exiting of gases. This can only happen at certain high SAV ratios, so as the cell grows, the SAV ratio decreases, which results in gas exchange being reduced. Ultimately, the cell loses its ability to function.

As mentioned above, a cell can only properly function when a high SAV ratio is maintained. When a cell is as large as a small fish, the SAV ratio will not be high enough. This will result in the cell undergoing cell division in order to maintain a high SAV ratio. Therefore, bacteria, which are prokaryotes (single-celled organisms) must be small to maintain the high SAV ratio.

Large organisms need their entire body to be composed of cells, and if the organism is unicellular, that will result in a huge cell that has a tremendously low SAV ratio. To eliminate this problem, the organisms are multicellular with tiny cells that lead to higher SAV ratios. Furthermore, these organisms have developed features that allow them to speed up and aid movement of materials in and out of the organism and the cells. These features include gas exchange organs (our lungs) and our circulatory system (our blood).