Cell:-
➥The basic, structural and functional units of life is cell.
➥Every living organism is made up of cells.
Cell Theory
➥All living things are composed of cell.
➥Cells are the basic structual and functional units.
➥New cells are produced from exiting cells.
Discovery of Cell
➥Robert Hooke (1665): Discovered and named cells in cork.
➥Anton van Leeuwenhoek (1674): First to see living cells.
➥Matthias Schleiden (1838): Found that all plants are made of cells.
➥Theodor Schwann (1839): Found that all animals are made of cells.
➥Rudolf Virchow (1855): Stated that all cells come from existing cells.
Types of Cells
➥ Prokaryotic Cells: Do not have a nucleus. Example: Bacteria.
➥ Eukaryotic Cells: Have a nucleus. Examples: Animal and Plant cells.
Structure of a Cell
➥ A cell consists of the following parts:
- Cell Membrane: The outer boundary of the cell that controls the entry and exit of substances.
- Cytoplasm: Jelly-like fluid inside the cell where organelles are suspended.
- Nucleus: The control center of the cell containing genetic material (DNA).
- Organelles: Specialized structures within the cell, each with specific functions.
Functions of Cell Organelles
Organelle | Function |
---|---|
Cell Membrane | Protects and organizes the cell, controls entry and exit of substances. |
Cytoplasm | Supports and suspends organelles, site of many cellular processes. |
Nucleus | Controls cell activities, contains genetic material. |
Mitochondria | Produces energy through respiration. |
Ribosomes | Synthesizes proteins. |
Endoplasmic Reticulum | Transports materials within the cell. |
Golgi Apparatus | Modifies, sorts, and packages proteins and lipids. |
Lysosomes | Digest and remove waste. |
Chloroplasts (in Plant Cells) | Site of photosynthesis. |
Vacuoles | Stores nutrients, waste products, and helps in maintaining turgor pressure. |
Differences Between Plant and Animal Cells
➥ Difference between a plant cell and an animal cell:-
Feature | Plant Cells | Animal Cells |
---|---|---|
Cell Wall | Present | Absent |
Chloroplasts | Present | Absent |
Vacuoles | Large, central | Small, numerous |
Shape | Rectangular | Round |
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