plants🌱

• define xylem tissue and some of its structure

  tubes that transport water + minerals in one direction from roots to the leaves of a plant. Made of lignified cells (wood) to strengthen the plant  
• define phloem tissue and some of its structure

  tubes that transport sugars + other nutrients around a plant in both directions. Made of sieve plates, allows water to flow vertically throughout the phloem.
• what are vascular plants

  plants that contain vascular tissue
• label the arrangement of xylem and phloem in parts of the plant

  .

  A) phloem

  B) xylem

  C) phloem

  D) xylem

  E) xylem

  F) phloem

  
• describe the movement of water in plants

  • Nutrients + water travel up the xylem from the roots to the leaves.

  Water evaporates from the mesophyll cells and exits the plant through stomata in the leaves.
• describe the intake of water in plants

  • The roots of the plants absorb the water and nutrients from the soil.  
  • The root system has many different branches that increase the overall surface area for absorption + root hair cells further increase surface area.  
  • Water and nutrients enter the xylem of the roots by either the extracellular or cytoplasmic pathways.  
• describe the extracellular pathway: intake of water

  • Water moves between cell walls 
  • Quick movement, less selective 
  • Water enters via this pathway 
• describe the cytoplasmic pathway: intake of water

  • Nutrients and minerals move through the cell cytoplasm via the plasmodesmata 
  • Slower movement, more selective.  
  • Nutrients and minerals enter via this pathway 
• define transpiration

  the evaporation of water from the leaves and movement of liquids up the xylem.  
• how is water lost in plants

  via transpiration
• what helps water to flow in the xylem 

  The lower pressure in the leaf, cohesion and capillary action
• environmental conditions that increase rate of transiration and therefore contribute to more loss of water via plants

  • High temperatures 
  • High light conditions 
  • Windy conditions 
  • Dry conditions 
• define translocation


  the movement of substances from a source to other tissues in the plant via the phloem.  
• describe translocation

  • This tends to take place in the phloem from a source to a sink 
  • Glucose is produced in the leaf cell (source)  
  • Glucose is transported into required cells and unloaded into sink cells.  
• how do plants regulate water balance

  • The two guard cells that surround the stomal pore regulate the opening and closing of stomata 
• describe how stomata increases transpiration to lose more water

  • Actively pump potassium ions into guard cells, greatly increasing the conc of solutes 
  • Water then diffuses into guard cells via osmosis, each guard cell becomes turgid.  
  • Stomata is open and gas exchange can occur 
• describe how stomata decrease transpiration to lose less water

  • Actively pump potassium ions out of guard cells 
  • Water then diffuses out of guard cells via osmosis, each guard cell becomes flaccid 
  • Stomata is closed and gas exchange cannot occur
• label the structure of the stomata

  .

  A) stomata

  B) vacuole

  C) guard cell

  D) nucleus

  E) chloroplasts

  F) guard cell