Specialized Cells
Introduction
- Specialized cells have a structure that suits their function.
- Different cells have different functions and structures.
- The process of cell differentiation explains how cells become specialized (covered in another video).
- This lecture focuses on examples of specialized cells in plants and animals.
Specialized Plant Cells
Plant Cell Specializations
- Epidermal Cells
- Form a boundary to prevent water loss.
- Can be either single or multiple cell layers thick.
- Often lack chloroplasts.
- Guard Cells
- Control the opening and closing of stomata.
- Help balance gas exchange and water loss.
- Trichomes
- Hair-shaped epidermal cells.
- Can have protective functions, like secreting toxins or reflecting light.
- Example: Sundew plant trichomes digest insects.
- Mesophyll Cells
- Palisade Mesophyll: Capture light, contain many chloroplasts.
- Spongy Mesophyll: Loosely packed, facilitates gas exchange, fewer chloroplasts.
- Vascular Cells
- Xylem: Transports water.
- Phloem: Transports products of photosynthesis.
Specialized Animal Cells
Human Body Cell Specializations
- Red Blood Cells (RBCs)
- Contain hemoglobin to carry oxygen.
- Disc-shaped for increased surface area.
- Lack nucleus and many organelles.
- White Blood Cells (WBCs)
- Different structures and functions compared to RBCs.
- Granulocytes: Have granules that destroy pathogens.
- Often irregularly shaped for particle engulfing.
- Muscle Cells
- Smooth Muscle: Spindle-shaped, high mitochondria count for ATP.
- Skeletal Muscle: Striated, long, bundled, multi-nucleated.
- Cardiac Muscle: Sync via intercalated discs, branched.
- Neurons
- Transmit signals, found in the brain/spinal cord.
- Can be over a meter long.
- Structures: Dendrites receive impulses, Axons transmit impulses.
Conclusion
- Specialized cells form specialized tissues.
- Further information on tissues and biological organization in another video.
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