vascular seedless plants

• Vascular tissue

  • moves nutrients, water and glucose
  • structural support for plants (Ex. wood)
  • shoots bring sugars down to roots and leaves
  • leaves and shoots get water from leaves
  • vascular system: xylem (bottom to top), phloem (top to bottom)
• Xylem two important cells

  1. tracheids
  2. vessel
• tracheids (xylem)

  • once evolved once
  • lets water go through
  • in all vascular land plants
  • small pits, lots of holes
  • primary wall (cellulose)
  • secondary wall (lingin)
  • lingin: gives structure, able to rise
• vessel (xylem)

  • made of cellulose
  • straw-like
  • larger holes so more efficient
  • wider tube
• Phloem (live part of plant)

  • transports sugars
  • two cells: sieve and companion
• sieve cell (phloem)

  • water and sugar transport
  • alive no nucleus
  • has few organelles
  • transports water and sugar to fruits
• companion cell (phloem)

  • alive part of the tree
  • "heart" - has nucleus
  • push nutrients to phloem
• transport-cohesion

  • evaporation of water from leaves into the air through stomata
  • leaves: let out oxygen and water and intakes carbon dioxide
  • water is cohesive --> so they move together
  • no energy from plant is needed
  • 15m/hr water moved
  • water helps support xylem with lignin
  • cells need water and photosynthesis
  • > 90% of water lost during process
• process of xylem and phloem

  1. leaf --> sucrose movement to companion cell
  2. sucrose moves downwards (phloem), companion cell takes sugar to root cells
  3. water goes up xylem
• Seedless Vascular plants alternation of generations (ferns)

  1. dominant mature sporophyte (2n) meiosis creates spores
  2. spores dispersed by wind (n) (only one spore needed to develop gametophyte; independent)
  3. mitosis: mature gametophytes (n) produce: antheridia and archegonia
  4. mitosis: mature gametophytes (n)
  5. mitosis: sperm in antheridia (n), egg in archegonia (n)
  6. sperm swim to egg, a little water because less distance
  7. fertilization: diploid 2n archegonium zygote (2n)
  8. mitosis: gametophyte (n) creates sporophyte (2n)
  9. mature sporophyte (2n)
• seedless vascular plants

  1. embryophytes
  2. sporophyte is dominant (major evolutionary trend)
  3. there is still separate gametophytes
  4. still dependent on water
• Commensal ferns (symbiosis)

  • fern benefits from what it's growing on (Ex. tree)
  • one benefits, the other doesn't get bothered
  • parasitism and mutualism