A cell is the basic structural and functional unit of all living organisms. It is the smallest unit capable of independent life and reproduction

. Cells consist of cytoplasm enclosed within a membrane, which controls the substances entering and leaving the cell

. Cells contain specialized structures called organelles, each performing specific functions. Key organelles include:

• Nucleus : Contains genetic material (DNA) and controls cell activities

• Mitochondria : Generate energy for the cell

• Endoplasmic reticulum and Golgi apparatus : Synthesize and process molecules

• Ribosomes : Produce proteins

• Lysosomes and peroxisomes : Digest waste and recycle materials

• Chloroplasts (in plants): Conduct photosynthesis to convert sunlight into energy

Cells are broadly classified into two types:

• Eukaryotic cells : Have a nucleus and membrane-bound organelles; found in plants, animals, fungi, and protists

• Prokaryotic cells : Lack a nucleus and membrane-bound organelles; include bacteria and archaea

Cells can function independently, as in single-celled organisms, or cooperate to form tissues and organs in multicellular organisms

. The concept of the cell was first described by Robert Hooke in 1665, who named them after the small rooms (cells) in monasteries

. Cell theory states that all living organisms are composed of cells, cells are the fundamental units of life, and all cells arise from pre-existing cells

. In summary, a cell is the fundamental unit of life, capable of carrying out all processes necessary for life, from energy production to reproduction