Cell Structure and Types Prokaryotic and Eukaryotic .pptx

Cell Structure and Types Prokaryotic and Eukaryotic

1. Cell Structure and Types Prokaryotic vs Eukaryotic Cells, Cell Size, Shape, and Types

2. Prokaryotic vs Eukaryotic Cells Prokaryotic Cell: - No true nucleus, nucleoid region present - Components: Plasma membrane, cytoplasm, DNA, ribosomes - Example: Bacteria Eukaryotic Cell: - True nucleus with nuclear membrane - Organelles: Mitochondria, ER, Golgi body, etc. - Examples: Plants, animals, yeast

3. Number and Size of Cells - Bacteria, yeast = unicellular - Plants and animals = multicellular - Cell size varies: 0.2 µm to several µm - Animal cells: 10 µm to 100 µm - Cell volume remains constant, independent of organism size

4. Size of Different Cells Examples of cell sizes: - Mycoplasma: 0.1 µm - Bacteria: 0.2 – 2.5 µm - Small lymphocyte: 4.0 µm - Erythrocytes: 7.6 – 8.0 µm - Liver cells: 20 µm - Human oocyte: 140 µm - Neurons: Up to 2 m long (axons)

5. Cell Shape - Cells may be spherical, cuboidal, columnar, discoidal, spindle-shaped, branched, etc. - Plant cells: usually polyhedral due to cell wall - Animal cells: variable shapes (e.g., muscle cells, neurons)

6. Examples of Cell Shapes - Amoeba: Irregular shape - Spherical: Egg cells of many animals - Cuboidal: Glandular cells - Columnar: Epithelium lining intestine - Spindle-shaped: Smooth muscle cells - Branched: Neurons