A biologist compares electron micrographs of a plant leaf mesophyll cell and a human liver cell. The presence of various organelles and structures in each cell is recorded in the table below.
| Structure/organelle | Plant leaf cell | Human liver cell |
|---|---|---|
| Cell wall | Present | Absent |
| Chloroplasts | Present | Absent |
| Large permanent vacuole | Present | Absent |
| Centrioles | Absent | Present |
| Plasmodesmata | Present | Absent |
| Glycogen granules | Absent | Present |
| 80S ribosomes | Present | Present |
| Mitochondria | Present | Present |
| Nucleus | Present | Present |
Outline the key differences between the plant leaf cell and the human liver cell, explaining how each difference is related to the function of the cell.