One significant difference between human cheek cells and onion cells is their cellular structure, particularly in the presence of a cell wall.
Human cheek cells, being animal cells, do not have a cell wall. Instead, they are surrounded by a flexible cell membrane that allows for a range of movement and interaction with the surrounding environment. This membrane is integral in regulating what enters and exits the cell.
Onion cells, on the other hand, are plant cells and possess a rigid cell wall made of cellulose. This cell wall provides structural support and protection, allowing the plant to maintain its shape and resist external pressure.
In summary, while both types of cells share certain similarities inherent to eukaryotic cells, the presence of a cell wall in onion cells is a key difference that highlights the distinct characteristics of plant and animal cells.