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Transportation in Plants (Types of Cells in Plants (Vascular (conducts…

- - - - Function
        
        To transport water and dissolved mineral salts from the roots to the stem and leaves
        
        Provides mechanical support for the plant
      - forces that pulls the water up
        
        Capillary Action (cohesion+adhesion)
        
        Transpiration Pull
        
        Root Pressure
      - Structure
        
        long hollow tube (made up of many dead cells fused together at the ends)
        
        a continuous lumen with no cross-walls or protoplasm
        
        move water easily through xylem
        
        lignin deposits in inner walls of xylem vessels
        
        to prevent collapse of xylem vessel
        
        3 types
        
        annular
        
        spiral
        
        pitted
      - Transports of water is unidirectional (only upwards)
      - absorption of water
        
        by osmosis when there is a higher water potential in soil than in root hair cell
    - - function
        
        transports nutrients (mainly sucrose) from the leaves to the other parts of the plant for storage and utilization. Food stores can be mobilized from the storage organs and translocated to other parts of the plant for usage.
      - structure
        
        elongated cells with sieve plates between them
        
        type of cells present
        
        Sieve Tube Elements
        
        sieve tube cells
        
        elongated cells
        
        lack nuclei
        
        have thin layer of degenerated cytoplasm (has this little to reduce resistance to the flow of substances)
        
        sieve tube plates
        
        cross-walls with many small sieve pores. It has pores to allow rapid flow of manufactured food substances
        
        mechanical injury (like insect bites) always happens to plants. To protect the phloem, the sieve plates produce callose to block the flow of nutrients, to prevent loss.
        
        companion cells
        
        mature sieve tubes don't have many of its organelles
        
        hence companion cells help keep the sieve tube cells alive by providing it with nutrients and energy
        
        have numerous mitochondria to provide energy for the loading of sucrose into the sieve tubes
      - It is transported bidirectionally (travels up and down)
      - absorption of mineral salts
        
        by diffusion when there is a higher concentration of mineral salts in soil than in root hair cell
        
        by active transport when there is a lower concentration of mineral salts on the root than the root hair cell
    - - around the ring of Phloems and Xylems there is the epidermis
      - function
        
        reduces evaporation of water
    - - many bundles form around the perimeter of the cortex
      - function
        
        transports manufactured food/water/amino acids/ mineral salts
        
        cambium goes through cell division to replace old phloem and xylem