Interactions between organisms and their environment ECOLOGY Interactions between organisms and their environment

Populations Size, Density, Dispersion = factors Growth: Limited by resources and other factors Exponential or Logistic K and r Specialists: Two methods of species growth

Ecosystem Structure Abiotic vs. Biotic Factors: Fungi, bacteria, animals, plants… Weather, water, pH, temp, soil, air Organism, Population, Community, Ecosystem, Biome, Earth (small to largest!) Habitat vs. Niche

Food Chain vs. Food Web Feeding level = trophic level Producer Consumer Detritivores Symbiosis: Mutualism, commensalism, parasitism

Food Web

Relationships in Ecosystems Autotrophs vs. Heterotrophs Photosynthesis and cellular respiration Primary Producer (autotrophs) Primary Consumer (heterotrophs) (herbivore) Secondary/Tertiary/Quaternary Consumer (carnivores, omnivores, scavengers) Detritivore aka. Decomposer – in their own category!

Ecological Pyramids These displays relationships between food web or food chain levels 10% RULE - Each level contains only 10% of energy, mass, or population numbers from the level below For Ex. 1,000 grass plants # of Grasshoppers? # of Frogs? # of Birds?

Biogeochemical Cycles Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur = CHNOPS! Focus: Water (H20), Carbon/Oxygen and Nitrogen Cycles Main Idea: Abiotic/Biotic factors NEED these elements, so they must be MOVED AND EXCHANGED over time throughout ecosystems

Cell Respiration Photosynthesis Where does it happen? Bacteria – cytoplasm plant/animals - mitochondria Bacteria – cytoplasm Plant - chloroplasts What is the process? See picture on other slide for formula In which cell types? Eukaryotic/prokaryotic cells, Plant and animal cells. All organisms! Eukaryotic/prokaryotic cells Plant cells! Why does it happen? To provide an easily useable form of energy for the cell (ATP) To provide energy in the form of glucose for the cell to use How does it happen? Glucose is broken down in the presence of O2 to release ATP, H2O and CO2 Sunlight energy is captured to convert CO2 and H2O into glucose and O2

Leaf – Cross Section Diagram