Vacuoles are non-cytoplasm areas present inside the cytoplasm which are separated from the latter by specific membranes. Vacuoles are believed to be formed by expansion and pinching off endoplasmic reticulum. Vacuoles occur in almost all types of cells. They are small in animal cells and large in fungal and plant cells.
Vacuoles are fluid filled vacuoles or vesicles which are separated from the cytoplasm by a selectively permeable membrane called tonoplast.
A number of small sap vacuoles occur in animal cells and young plant cells.
The fluid contains minerals, sugars, oxygen, carbon dioxide, soluble pigments and organic acids. The pigments include anthocyanins and anthoxanthins.