Download Title: Surface Area to Volume Ratio Questions: Why can`t cells

Name______________________________ Activity # _______ Date: _________
Title: Surface Area to Volume Ratio
Questions: Why can’t cells continue to grow larger and larger to become giant cells, like the blob?
Why are most cells like those in an elephant or an earthworm, microscopic in size? What happens
when a cell grows larger? What causes cells to remain small?
Procedure:
1. Cut out the cubic cell models and fold them and tape them together. You should have 4
different models when finished.
2. Compute the following information about each model and write your data on the chart
provided. Here are some formulas you might need.
3. Surface area of one side- A=s2 (A- area, s-side) you will measure your cube in unit. Your
smallest cube is one unit long on a side. The largest cube is 4 units long on a side.
4. Total surface Area- A=6 x s2
5. Volume- V= s3
6. The chart also contains the ratio of the total surface area to the volume. A ratio does not
have units. The ratio should be simplified (reduced) to its smallest possible numbers.
Data:
Cell size
s= units
Area of one side
Total surface
area
Volume of cube
Total surface
area to volume
ratio
1
2
3
4
Questions:
1. Anything that the cell takes in, like oxygen and food, or lets out such as carbon dioxide,
must go through the cell membrane. Which measurement of the cubes best represents the
cell membrane?
2. The cell contents, nucleus and cytoplasm, use the oxygen and food while producing wastes.
Which measurement of the cube best represents the cytoplasm?
3. As the cell gets larger, and gets more cell contents, will it need more or less cell membrane
in order to survive?
4. As the cell grows larger, does the total surface area to volume ratio get larger, smaller or
stay the same?
5. Why can’t cells survive when the total surface area to volume ratio becomes too small?
6. Which cube size has the largest surface area to volume ratio?
7. Which cell size has the greatest chance of survival?
8. What do cells do to increase their surface area to volume ratio?