Cell Unit of Life

Discovery of Live Cells

• Antonie van Leeuwenhoek is credited with first observing and describing live cells in the late 17th century.
• His discoveries were made using a simple microscope he invented, which allowed him to see microorganisms in pond water.

Fundamental Unit of Life

• Cells are considered the basic unit of all living organisms, forming the building blocks for life.
• Every organism, whether unicellular or multicellular, is composed of cells that perform essential functions for survival.

Cell Membrane

• The cell membrane separates the internal environment of the cell from the external environment.
• It acts as a selective barrier, regulating the movement of substances in and out of the cell.

Plant Cell Example

• A typical example of a plant cell is the Guard Cell, which controls the opening and closing of stomata for gas exchange.
• Plant cells are characterized by a rigid cell wall, chloroplasts for photosynthesis, and large central vacuoles.

Animal Cell Example

• A typical example of an animal cell is the Red Blood Cell (erythrocyte), which transports oxygen throughout the body.
• Unlike plant cells, animal cells lack a cell wall and contain various organelles for diverse functions.