Cell - The Unit of Life
The cell is the basic structural and functional unit of all living organisms. It is the smallest part of the body
of an organism, capable of independent existence and is capable of performing the essential functions of life.
▪ The cell was first discovered by Robert Hooke who observed them in thin slices of cork. He coined the
term cell.
▪ Leeuwenhoek first observed living organisms using a microscope.
A cell consists of three parts:
1. the cell membrane,
2. the nucleus, and,
3. between the two, the cytoplasm.
Cell theory was proposed by Schleiden and Schwann:
▪ All life forms are made of cells.
▪ Cells arise from pre-existing cells.
▪ The cell is the structural and functional unit of life.
Within the cytoplasm lie intricate arrangements of fine fibres and hundreds or even thousands of extremely
small or tiny but distinct structures called organelles.
A cell is capable of independent existence and can carry out all the functions which are necessary for a living
being. A cell carries out nutrition, respiration, excretion, transportation, and reproduction. Unicellular
organisms are capable of independent existence. The cell functions include movement of substances across
the cell membrane, cell division to make new cells, and protein synthesis.
Functions of human cell:
Human cells are multitasking when it comes to functions. Though there are infinite functions they perform,
six of them are considered important. The six main functions of human cell include:
They provide structure and support.
They facilitate growth through mitosis.
They allow passive and active transport.
• They produce energy.
They create metabolic reactions.
They create aid in reproduction.
The cell is the basic structural and functional unit of all living organisms. It is the smallest part of the body
of an organism, capable of independent existence and is capable of performing the essential functions of life.
▪ The cell was first discovered by Robert Hooke who observed them in thin slices of cork. He coined the
term cell.
▪ Leeuwenhoek first observed living organisms using a microscope.
A cell consists of three parts:
1. the cell membrane,
2. the nucleus, and,
3. between the two, the cytoplasm.
Cell theory was proposed by Schleiden and Schwann:
▪ All life forms are made of cells.
▪ Cells arise from pre-existing cells.
▪ The cell is the structural and functional unit of life.
Within the cytoplasm lie intricate arrangements of fine fibres and hundreds or even thousands of extremely
small or tiny but distinct structures called organelles.
A cell is capable of independent existence and can carry out all the functions which are necessary for a living
being. A cell carries out nutrition, respiration, excretion, transportation, and reproduction. Unicellular
organisms are capable of independent existence. The cell functions include movement of substances across
the cell membrane, cell division to make new cells, and protein synthesis.
Functions of human cell:
Human cells are multitasking when it comes to functions. Though there are infinite functions they perform,
six of them are considered important. The six main functions of human cell include:
They provide structure and support.
They facilitate growth through mitosis.
They allow passive and active transport.
• They produce energy.
They create metabolic reactions.
They create aid in reproduction.
