The vacuole
This is what pushed the nucleus of the onion peel cells aside — the largest of the organelles a plant cell holds.
Figure to be added
The vacuole
A vacuole is a large organelle found in plant cells, surrounded by a membrane and filled with fluid.
Its membrane is called the tonoplast, and the fluid inside it the cell sap.
What is in the cell sap?
The cell sap stores water, sugars, ions of various kinds, and pigments.
Functions of the vacuole
- Maintaining the water balance of cells
- Maintaining support
- Giving cells their colour, through the pigments
Vacuoles in animal cells
Vacuoles are not normally to be found in animal cells, though small ones may sometimes be present. Contractile vacuoles are found in unicellular organisms.
Activity 02 is now complete
What you saw in the onion peel is fully accounted for: the rigid outline was the cell wall, and the nucleus was pushed to one side by the vacuole in the middle. Everything seen under that microscope now has a name.