This chapter explains that cells are the basic structural and functional units of all living organisms. It describes how cells were discovered and how living organisms can be unicellular or multicellular. The chapter discusses the shape, size, and function of cells, and explains the internal structure of a cell, including the plasma membrane, nucleus, cytoplasm, and cell organelles. It highlights how different organelles perform specific functions and how coordination among them helps the cell survive, grow, and reproduce.
Key Points
All living organisms are made up of cells.
The cell is the basic structural and functional unit of life.
Cells were first discovered by Robert Hooke in 1665.
Unicellular organisms consist of a single cell.
Multicellular organisms are made up of many specialised cells.
Cells differ in shape, size, and function according to their role.
Every cell arises from a pre-existing cell.
The plasma membrane surrounds the cell and is selectively permeable.
Diffusion and osmosis help substances move in and out of the cell.
Plant cells have an additional outer layer called the cell wall.
The nucleus controls cell activities and contains genetic material.
Chromosomes carry hereditary information in the form of DNA.
Prokaryotic cells lack a true nucleus and membrane-bound organelles.
Eukaryotic cells have a well-defined nucleus and organelles.
Cytoplasm is the fluid part where cell organelles are suspended.
Mitochondria release energy and are called the powerhouse of the cell.
Ribosomes help in protein synthesis.
Endoplasmic reticulum helps in transport and synthesis of materials.
Golgi apparatus modifies, packages, and transports substances.
Lysosomes digest waste materials and are called suicide bags.
Plastids are present in plant cells and help in photosynthesis and storage.
Vacuoles store food, water, and waste materials.
Cells divide for growth, repair, and reproduction.
👉 👉Cells work in an organised and coordinated manner to support life. Understanding the structure and function of cells helps us appreciate how living organisms grow, repair themselves, and survive in different environments.