bio 13

• Root


  Main function is the absorption of water and dissolved nutrients
• Root tissues


  • Epidermis
  • Cortex
  • Endodermis with Casparian strips
  • Pericycle
  • Xylem
  • Phloem

  
• Epidermis


  Outer skin, protects inner tissues from outer environment and physical damage
• Cortex


  Tissue underneath epidermis, stores food and water
• Endodermis


  Inner skin, delimits inner cylinder of root, has Casparian strips that control water and dissolved substance movement
• Pericycle


  Tissue inside endodermis, produces lateral roots
• Xylem


  Transports water and dissolved nutrients upward from roots to leaves
• Phloem


  Transports carbohydrates (sugars) produced in photosynthesis throughout the plant
• Vascular tissues


  Xylem and phloem, found in all plant organs

  
• Absorption of water and dissolved nutrients

  1. Water moves from soil to root hairs by osmosis

  2. Water moves through root tissues by apoplastic or symplastic transport

  3. Casparian strips in endodermis control which substances enter vascular cylinder
• Macronutrients


  • Phosphorus (P)
  • Nitrogen (N)
  • Potassium (K)
• Micronutrients


  • Iron (Fe)
  • Copper (Cu)
  • Manganese (Mn)
• Plants require nutrients to grow and survive
• Flower


  Sexual reproductive structure of flowering plants
• Flower


  • 4 main parts: Sepals, Petals, Stamens, Pistils
• Sepals - Calyx


  Outermost whorl or part, usually green and photosynthetic, leaflike, cover and protect the more delicate tissues that are developing within the bud
• Petals - Corolla


  Often brightly colored, showy and conspicuous, broad, flat and thin, resemble leaves in their overall organization, may be photosynthetic, serve to attract insects
• Stamen - Androecium


  Pollen producing structure (male), anther and filament
• Pollen grains


  Male gametophyte, radially or bilaterally symmetrical bodies that represent units of dispersal from the anther to the stigma, wall: exine and intine, apertures: sulci and colpi
• Pistil - Gynoecium


  Central portion of flower (female), stigma, style, ovary, composed of one or more carpels
• Carpels


  • Monocarpous: one carpel per flower, Apocarpous: two or more distinct carpels, Syncarpous: carpels connate

  
• How to determine the number of carpels compromising a gynoecium

  1. Count the stigmas or stigmatic lobes

  2. Count the styles

  3. Count the lobes of the ovary

  4. Count the locules in the ovary

  5. Count rows of placentae
• Ovule


  Consist of a nucellus, which bears the embryo sac, enclosed by one or two integuments, nucellus: central portion of an ovule in which embryo sac develops; the megasporangium
• Embryo sac


  The megagametophyte, possesses eight nuclei arranged in seven cells
• Types of flowers according to presence/absence of flower parts

  • Complete: containing sepals, petals, stamens and at least one carpel/pistil
  • Incomplete: lacks one or more of the floral parts
  • Perfect: with both male and female parts
  • Imperfect: lacks one of the essential organs; either pistillate or staminate
• General arrangement of flower parts

  • Radial /actinomorphic symmetry: flower divisible on more than one axis into two equal halves that are mirror images of each other
  • Bilateral / zygomorphic symmetry: flower divisible into mirror images on only one axis
• Types of flowers according to position of ovary

  • Hypogynous flower: superior ovary; flower parts arise from a level below ovary base
  • Perigynous flower: semi-inferior ovary; flower parts attach halfway up the ovary
  • Epigynous flower: inferior ovary; flower parts arise from a level above ovary base
• Types of flowers according to position of complexity

  • Solitary /simple
  • Inflorescence: clusters of flowers; has one main stalk (peduncle); also bears numerous smaller stalks (pedicels) each with a flower at its tip
• Types of inflorescence


  • Panicle: a branched main axis with side branches bearing loose clusters of flowers
  • Raceme: an unbranched elongated main axis whose flowers have pedicels that are all about the same length
  • Spike: an unbranched, elongated main axis whose flowers have very short or no pedicels
  • Corymb: unbranched, elongated axis whose flowers have pedicels of unequal length, forming an inflorescence that appears flat-topped
  • Simple umbel: peduncle bearing all of the pedicels at its apex
  • Compound umbel: a cluster of simple umbels at the apex of a main axis
  • Head: a peduncle bearing flowers that have no pedicels
  • Catkin: spikelike inflorescence that bears only unisexual flowers
  • Spadix: type of spike inflorescence having small flowers borne on a fleshy stem
• Fruit

  Anything that has seeds in it
• Fruit

  Ovaries that develop once the flower has been pollinated
• Number of seeds in a fruit

  Depends on how many eggs are at the base of the pistil and how many get fertilized
• Pericarp

  All the tissues surrounding the seed
• Drupe

  Fleshy fruit with a single seed or pit
• Berry

  Fleshy fruit with multiple seeds
• True berry

  Berry with a thin exocarp
• True berries

  • Tomatoes, grapes, peppers, blueberries, bananas
• Pepo


  Berry with a thick rind
• Hesperidium

  Berry with a thick leathery skin
• Pome


  Fruit from an inferior ovary, found in the Rose family