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  Centrosome and Centrioles NEET Notes: 9×3 Arrangement Explained  Structure of centrosome and centriole showing the characteristic 9×3+0 microtubule arrangement and cartwheel organization. - Dr.Sanjaykumar Pawar  Centrosome and Centrioles  Centrosome Centrosome is a cell organelle present mainly in animal cells . It is located near the nucleus . A centrosome usually contains two centrioles . The two centrioles are surrounded by a protein-rich material called pericentriolar material (PCM) . The centrosome acts as the microtubule-organizing centre (MTOC) of the cell. It helps in the formation of spindle fibres during cell division. Structure of Centrioles Centrioles are cylindrical structures . The two centrioles in a centrosome are arranged perpendicular (90°) to each other . Each centriole shows a cartwheel-like arrangement . A centriole is made up of nine peripheral fibrils . These fibrils are composed of tubulin protein . Each peripheral fibri...

  Cilia vs Flagella: Easy NEET Biology Notes with Diagram & Mind Map  Structure of cilia and flagella showing the 9+2 microtubule arrangement and basal body in a eukaryotic cell. - Dr. Sanjay Kumar Pawar  Cilia and Flagella – Basic Idea Cilia and flagella are hair-like structures present on the surface of the cell. They are extensions of the cell membrane . Cilia Cilia are short and numerous hair-like structures . They move in a coordinated, oar-like motion (like rowing a boat). Function: Help in movement of the cell (e.g., Paramecium). Or move fluid/particles around the cell (e.g., in respiratory tract). Flagella Flagella are long, whip-like structures . Usually present in fewer numbers (1 or 2 per cell) . Function: Responsible for movement of the whole cell (e.g., sperm cell). Difference between Prokaryotic and Eukaryotic Flagella Prokaryotic flagella (bacteria) : Structurally different from eukaryotic flagella. Eukaryotic fla...

Difference Between Prokaryotic and Eukaryotic Cells: NEET Notes for Beginners Comparison of Prokaryotic and Eukaryotic Cells with key structures explained for NEET Biology preparation. - Dr.Sanjaykumar Pawar  Bacterial Cell Structures (Continuation) Some bacterial membrane extensions help in: Cell division (formation of daughter cells) DNA replication and distribution Respiration Secretion processes Increasing surface area of plasma membrane Increasing enzyme content Chromatophores (in some bacteria) Found in cyanobacteria They are membrane extensions inside cytoplasm Contain photosynthetic pigments Help in photosynthesis Movement in Bacteria Some bacteria are motile (can move) Some are non-motile (cannot move) Flagella Long, thin, thread-like structures outside cell wall Help in movement (motility) Present only in motile bacteria Structure of flagellum Made of 3 parts: Filament → longest outer part Hook → connects filament to basal body ...