Cell:The Unit of Life – Notes

An Overview of Cell
Cell is the fundamental unit of life in all living organisms.
Modern cell theory states that:
• Living organisms are composed of cells and products of cells.
• Cells arise from pre-existing cells.
The plant cell is surrounded by a cell wall on the outside and a plasma membrane on the inside.
Plant and animal cells contain a spherical structure called the nucleus, which contains thread-like structures called chromosomes.
If the nucleus is membrane-bound, then the cell is called an eukaryotic cell.
Cells without a membrane-bound nucleus are called prokaryotic cells.
Eukaryotic cells contain membrane-bound organelles such as:
• Endoplasmic reticulum
• Golgi complex
• Lysosomes
• Mitochondria