Surface Area to Volume Ratio Lab
Background:
Why can’t cells continue to grow larger and larger to become giant cells, like a blob?
Why are most cells, whether from an elephant or an earth worm, microscopic in size?
What happens when a cell grows larger and what causes it to divide into 2 smaller cells rather than
growing infinitely larger?
Hypothesis:
As the cell gets larger, what will happen to its surface area to volume ratio?
Which cell will have the largest surface area to volume ratio?
Materials:
1. Photocopy of 4 cell models
2. Tape or glue
3. Scissors
Procedure: Work with a partner.
1. Cut out 4 cell models. Fold and put together
2. Make a hypothesis. (Answer the questions from the hypothesis section)
3. Calculate the data measurements for each cell.
4. Enter the data in table 1
5. Calculate the Surface Area to Volume ratios for each cell
6. Enter the data in table 2
Data:
Table 1:
Formulas
Cell size
(length of one side)
1
2
3
4
Length X Width =
Area of one face
(Units Squared)
LXWX6=
Total surface area
(Units Squared)
L X W X Height =
Volume of cell
(Units cubed)
Table 2:
Cell Size
Surface Area to Volume Ratio
(length of one side)
( = SA ÷ Vol.)
1
2
3
4
Analysis Questions: (Answer using Complete Sentences)
1. Anything that the cell takes in, like O2, and food, or releases out, such as CO2, must go through the cell
membrane. Which measurement of the cells best represents how much each cell membrane the models
have?
2. The cell contents use oxygen and food while producing waste. Which measurement best represent the
cell’s contents?
3. As the cell grows larger, does the total surface area to volume ratio get larger, smaller or remain the
same?
4. Why can’t cells survive when the ratio becomes too small?
5. Which size cell has the greatest surface area?
6. Which size cell has the greatest volume?
7. Which size cell has the greatest surface to volume ratio?
8. Which size cell has the smallest surface to volume ratio?
9. Which size cell has the greatest chance of survival?
10. What can cells do to increase their total surface area to volume ratios?