Ecology

• Ecology


  The study of relationships of organisms among themselves and their physical environments
• Levels of Organization for Organisms

  • Population-groups of the same species
  • Community-group of population, the intermingling of different species
  • Ecosystem-composed of different communes
  • Biome-a large community of plants and animals having the common characteristics
  • Biosphere-made up of all the ecosystems and the environment they exist in (ex aquatic or terrestrial biomes)
• Trophic Levels


  • Autotrophs (producers)-organisms that can make their own food through photosynthesis
  • Heterotrophs (consumers)-organisms that cannot make their own food and so depend on producers for their food
  • Primary consumer-one that eats the producer, herbivores (eat plants only)
  • Secondary consumer-one that eats the primary consumer, may be carnivores (eat meat but not plants) or omnivores (eat both meat and plants)
  • Tertiary consumer-one that eats the secondary consumer, the top consumer
  • Saprophytes-organisms that feed on dead matter
  • Decomposers-organisms that break down dead organic matter (fungi, bacteria, some insects)
• Botany


  The scientific study of plants, their physiology, structure, genetics, ecology, distribution, classification, and economic importance
• Xylem


  Conducts water and minerals from roots to the rest of the plants
• Phloem


  Transports sugar and other nutrients from the leaves to the rest of the plant
• Vegetative Organs


  • Leaves
  • Stems
  • Roots
• Reproductive Organs


  • Stamen (in males)
  • Pistil (in females)
• Parts of a Leaf

  • Nodes-points of attachment of aboveground plant parts
  • Internodes-region between two successive nodes
  • Lamina-main part of the leaf also known as leaf-blade
  • Petiole-stalk where the leaf is attached to the stem
  • Midrib-the large vein at the center of the leaf-blade
  • Margin-the vein at the edges
• Phyllotaxy


  • Alternate: one leaf per node
  • Opposite: 2 leaves per node
  • Whorled: 3 or more leaves per node
• Accessory Parts of a Flower

  • Petals-the colored part of the flower
  • Corolla-a collection of petals
  • Sepals-the green leaf-like structure surrounding the bottom part of the petals
  • Calyx-collection or whorl of sepals
• Sex Organs of a Flower

  • Stamen-male sex organ
  • Pistil-female sex organ
• Androecium


  Composed of all stamens in the flower
• Anther


  Structure which holds the pollens
• Filament


  Supports the anther
• Gynoecium


  Refers to the collection of pistils in the flower
• Style


  A tube connecting the stigma and the ovary
• Ovary


  An enlarged base which holds the ovules
• Fruits


  Ripened ovaries
• Seeds


  Mature ovules
• Differences between Monocots and Dicots

  • Flowers: Multiples of 3 (Monocot) vs Multiples of 4 or 5 (Dicot)
  • Leaves: Parallel veins (Monocot) vs Branched veins (Dicot)
  • Roots: Fibrous (Monocot) vs Tap (Dicot)
  • Stems: Spread from the center (Monocot) vs Arranged in a ring (Dicot)
  • Cotyledons: Single (1, Monocot) vs Double (2, Dicot)