Plants

• Plants are important because:

  • Plants make plant products
  • They're primary producers and help all life on earth
  • They help to maintain earth’s atmosphere
  • They move water from soil to atmosphere
  • Plants produce important habitats for life
• Shoot System (above ground)

  • stems, leaves, flowers
  • leaf stems (petiole)
  • most photosynthesis occurs in leaves because they have a larger surface area
  • absorbs sunlight, gas exchange, initializes reproduction
• Tap roots (eudicot plants), fibrous roots (monocot plants) - generally shallower.
• Modified Roots

  • Ivy - sticky roots, climbs things
  • Corn - strong crop root, can hold up heavy plant
  • Mangrove trees - roots modified to exchange gases (roots above water)
  • Sugar beets - storage roots, store carbohydrates + sugars
• Modified Shoots

  • Morphological diversity among shoot species
  • Tall plants to access lights, wood for support
  • Dry and windy? Grow shorter
  • Cactus - shoots store water to survive in drought conditions
  • Stolons (above ground stems (like a strawberry plant)) - stems go and drop root
  • Rhizomes - horizontal stems underground
  • Tubers - store energy, produce more energy than needed, stored in tubers
  • Thorns - protect plant
• Leaves

  • Compound leaf is 1 leaf divided into leaflets - doubly compound leaf like ferns
  • Compound leaves advantageous in windy conditions - they don’t get blown off the plant
  • Needle - not as much access to water, minimizes water loss by transpiration and wind
• Modified Leaves

  • Bulbs (onions), considered a leaf - store energy
  • Aloe Vera (succulent) - leaves that store water
  • Tendrils - modified leaves that wrap, grow using sensation of touch - grow, bend once touching something (combing plant, access to light, no woody stem for support)
  • Poinsettia - looks like flower but “petals” are red leaves - not very efficient at photosynthesis cause red, not green - attract pollinators
  • Traps - pitcher plant, Venus fly plant