Chapter name - Cell the unit of life
(Short notes)
1. Definition & Historical Context
Cell: The smallest structural, functional, and biological unit of life .
Discovered by Robert Hooke in 1665 (cork slice; coined “cellulae”) .
Anton van Leeuwenhoek (1674): first to see living cells (bacteria, protozoa) .
2. Cell Theory (Schleiden, Schwann, Virchow)
1. All organisms are composed of one or more cells.
2. Cells are the basic unit of structure and function in organisms.
3. All cells arise from pre-existing cells (omnis cellula e cellula) .
3. Types of Cells
Type Nucleus Organelles
Prokaryotic No No membrane-bound
Example-Bacteria, Archaea
Eukaryotic Yes Yes (mitochondria, ER) Example-Plant/Animal cells
4. Cell Components & Functions
Plasma Membrane – Selectively permeable lipid–protein barrier.
Cytoplasm – Jelly-like medium for organelles.
Nucleus (with nuclear membrane, nucleolus, chromatin) – Genetic control center.
Mitochondria – ATP production (“powerhouse”).
Endoplasmic Reticulum – Rough ER (protein), Smooth ER (lipid).
Ribosomes – Protein synthesis.
Golgi Apparatus – Processes & packages proteins.
(Short notes)
1. Definition & Historical Context
Cell: The smallest structural, functional, and biological unit of life .
Discovered by Robert Hooke in 1665 (cork slice; coined “cellulae”) .
Anton van Leeuwenhoek (1674): first to see living cells (bacteria, protozoa) .
2. Cell Theory (Schleiden, Schwann, Virchow)
1. All organisms are composed of one or more cells.
2. Cells are the basic unit of structure and function in organisms.
3. All cells arise from pre-existing cells (omnis cellula e cellula) .
3. Types of Cells
Type Nucleus Organelles
Prokaryotic No No membrane-bound
Example-Bacteria, Archaea
Eukaryotic Yes Yes (mitochondria, ER) Example-Plant/Animal cells
4. Cell Components & Functions
Plasma Membrane – Selectively permeable lipid–protein barrier.
Cytoplasm – Jelly-like medium for organelles.
Nucleus (with nuclear membrane, nucleolus, chromatin) – Genetic control center.
Mitochondria – ATP production (“powerhouse”).
Endoplasmic Reticulum – Rough ER (protein), Smooth ER (lipid).
Ribosomes – Protein synthesis.
Golgi Apparatus – Processes & packages proteins.
