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

-1cm cube has the largest percent diffusion, 100%.  All area was colored in pink which means diffusion was completed.

←From top to bottom, 1cm cube, 2cm cube and 3cm cube.

As the picture shows, no transparent area in 1cm cube. There are some intact area in both 2cm cube and 3cm cube.

↑The agar cubes are made from the solution containing phenolphthalein. So, when cubes are immersed in basic solution, the color of cube turns to pink from outside to inside. By measuring the area that turned pink, we can calculate the percentage of diffusion.↓

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

-The proportion of surface area against the volume of cube becomes largest in 1cm cube. More area is exposed to the solution so that the rate of diffusion results in the fastest. Moreover, less volume requires less time to the diffusion completes.

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

-The ratio of surface are and volume of cube get closer as the length, width and height increase. Therefore, rather than producing 1 big cell, making multiple cells is more effective in terms of increasing surface area of the cell.

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 cube is going to be the most effective at maximizing diffusion, how do you know this?

-The cube with ratio 4:1 would have fastest diffusion rate. Since that cube has the smallest volume against its surface area, more area is immersed to the liquid. Therefore, the diffusion in that cube(4:1) complete shorter period than the rest of two cubes.

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

-alveolus in lungs helps expand the surface area so that more amount of gas can be exchanged.

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

-Since bacteria is consisted from 1 cell. Therefore, the only way to take in the nutrients is diffusion. Therefore, too big cell can’t nourish itself because of fewer surface area of cell membrane.

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

-Can be replaced quickly.

-Restores damaged parts quickly

-Able to form the organism that has specific function by creating various types of cells. e.g. muscle

←Data chart of the experiment.