A eukaryotic cell is a complex type of cell that contains a true nucleus enclosed by a nuclear membrane and several membrane-bound organelles such as mitochondria, endoplasmic reticulum, Golgi bodies, chloroplasts (in plants), etc.
The word “Eukaryotic” comes from the Greek words:
Eu = true
Karyon = nucleus
Thus, eukaryotic cells possess a well-defined nucleus.
Eukaryotic cells are found in:
Animals
Plants
Fungi
Protists
Characteristics of Eukaryotic Cells
Presence of a true nucleus.
DNA arranged in chromosomes.
Presence of membrane-bound organelles.
Larger and more complex than prokaryotic cells.
Cell division occurs through mitosis and meiosis.
Cytoplasm is well organized.
Diagram of a Typical Eukaryotic Cell
 |
| Fig: A typical eukaryotic cell |
Major Organelles of a Eukaryotic Cell and Their Functions
| Organelle | Function |
|---|---|
| Cell Membrane | Controls movement of substances into and out of the cell |
| Cytoplasm | Jelly-like matrix where organelles remain suspended |
| Nucleus | Controls all cellular activities and contains DNA |
| Nucleolus | Formation of ribosomes |
| Mitochondria | Site of cellular respiration and ATP production |
| Ribosomes | Protein synthesis |
| Endoplasmic Reticulum (ER) | Transport of materials inside the cell |
| Rough ER | Protein synthesis due to attached ribosomes |
| Smooth ER | Lipid synthesis and detoxification |
| Golgi Apparatus | Packaging and secretion of proteins |
| Lysosomes | Intracellular digestion |
| Vacuoles | Storage of food, water, and wastes |
| Centrosome/Centrioles | Help in cell division (mainly animal cells) |
| Chloroplast (plant cells) | Photosynthesis |
| Cell Wall (plant cells) | Provides rigidity and protection |
Types of Eukaryotic Cells
1. Animal Cell
No cell wall
Small vacuoles
Centrosome present
2. Plant Cell
Cell wall present
Large central vacuole
Chloroplast present
Difference Between Prokaryotic and Eukaryotic Cells
| Feature | Prokaryotic Cell | Eukaryotic Cell |
|---|---|---|
| Nucleus | Absent | Present |
| Size | Small | Large |
| Organelles | Absent | Present |
| DNA | Naked circular DNA | Linear chromosomes |
| Examples | Bacteria | Plants, animals, fungi |
Eukaryotic cells are highly organized cells possessing a true nucleus and membrane-bound organelles. Their complex internal structure enables advanced cellular functions in plants, animals, fungi, and protists.
Diagrammatic presentation of a eukaryotic cell & functions
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Important Scientists Related to the Discovery of Eukaryotic Cells
1. Robert Hooke (1665)
- Observed cork cells using a microscope.
- Coined the term “cell” in his book Micrographia.
- These were dead plant cells.
2. Antonie van Leeuwenhoek (1674)
- First observed living cells and microorganisms.
- Called them “animalcules”.
3. Édouard Chatton (1925)
-
Introduced the terms:
- Prokaryote
- Eukaryote
- Distinguished cells based on the presence of a true nucleus.
Therefore, Édouard Chatton is credited with distinguishing and defining eukaryotic cells, while Robert Hooke first discovered cells in general.
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