8 Limits to Cell Size - Blue Agar Simulation key p. 63

Hypothesis: Small cells should "feed" faster.

Table 1. Feeding of cell models. Record all measurements in mm.

Table 2. Investigating SA/V and feeding efficiency. p. 64.

Table 3. SA/V and % feeding efficiency, graph.

Questions p. 65.

  1. Within a constant period of time, which cell was able to supply the greatest proportion of its volume with the "nutrient" H2SO4?
    The smaller cell received more nutrients.

    Which cell appeared to be in the most danger of starving?
    The bigger cell is in danger of starving.

  2. With reference to SA, V, and SA/V ratios, explain how the portion of the cell that receives nutrients changes as a cell grows larger (as in length).
    As cell gets larger, SA/V decreases, the portion receiving nutrients decreases.

  3. Was your hypothesis supported? Explain why or why not.
    Hopefully your hypothesis was supported. Small cells have higher SA/V ratio.

  4. What limits how large cells can be? Provide solutions to the problem of cell growth. Use data from your experiment to support your explanation.
    SA/V ratio puts a limit on cell size; as cells get bigger, SA/V ratio decreases.

Lab notes made Oct 11, 2009 by Peter Chen