The table below shows the concentration of carbon dioxide in arbitrary units (a.u.\text{a.u.}a.u.) in the intercellular air spaces (outside) and inside four different plant mesophyll cells, P, Q, R, and S.
| Cell | Carbon dioxide concentration outside (a.u.\text{a.u.}a.u.) | Carbon dioxide concentration inside (a.u.\text{a.u.}a.u.) |
|---|---|---|
| P | 8 | 17 |
| Q | 19 | 12 |
| R | 11 | 12 |
| S | 22 | 11 |
Based on the table, answer the following questions:
Which cell has the smallest difference in carbon dioxide concentration between the outside and the inside of the cell?
Into which cell will carbon dioxide diffuse into the fastest?