Vacuoles

The organelle which helps in maintaining turgidity of the cell and a proper internal balance of cellular contents is known as vacuole. 

i. The vacuoles are bound by semipermeable membrane, called tonoplast membrane. This membrane helps in maintaining the composition of vacuolar fluid (cell sap), different from that of the cytosol.

ii. Composition of cell sap differs in different types of cells. 

iii. In vacuoles along with excretory products other compounds are stored that are harmful or unpalatable to herbivores, thereby protecting the plants.

iv. Attractive colours of the petals are due to storage of such pigments in vacuoles. 

v. Generally, there are two or three permanent vacuoles in a plant cell.

vi. In some large plant cells, a single large vacuole occupies the central part of the cell. It is called central vacuole. In such cells, vacuole can occupy about 90% of the total volume of the cell.

vii. The cell sap of central vacuole is a store house of various ions and thus is hypertonic to cytosol.

viii. Small vacuoles in seeds of certain plants store organic materials like proteins.

ix. In animal cells, they are few in number and smaller in size. 

x. Intake of food or foreign particle by phagocytosis involves formation of food vacuole.

hypertoni- having a higher osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid.

Phagocytosis is a fundamental cellular process by which certain types of cells engulf and ingest solid particles, such as bacteria, debris, dead cells, and other foreign materials. This process plays a critical role in the immune system's defense against infections and maintaining tissue homeostasis.