Biology 1 ecology and photosynthesis

• Food chains and food webs


  Illustrate the flow of energy in ecosystems
• Photosynthesis


  Green plants use it to create energy from the sun
• Arrows in a food web or chain

  Show the direction of energy flow
• Consumers in a food chain

  • Primary consumer (eats green plant)
  • Secondary consumer (eats primary consumer)
  • Tertiary consumer (eats secondary consumer)
• Food web


  Interconnects multiple food chains in an ecosystem
• Types of organisms


  • Carnivores (eat only animals)
  • Herbivores (eat only plants)
  • Omnivores (eat both)
• All organisms in an ecosystem depend on each other
• Food chains


  Demonstrate feeding relationships between organisms
• Food webs


  Show how different food chains interact in an ecosystem
• Energy transfers through a food chain


  Energy lost at each level
• Pyramid of numbers


  Represents the population of each organism in a food chain
• Adaptations


  • Help species survive in their environments
• Adaptations of cacti


  • Small surface area to minimize evaporation
• Plants adapt in various ways to survive in different habitats
• Leaf structure


  • Aids in photosynthesis by absorbing light, carbon dioxide, and water
• Stomata


  Allow gases to pass in and out of leaves
• Guard cells


  Control the opening and closing of stomata
• Waxy cuticle


  Reduces water loss from leaves
• Palisade cells


  Contain chloroplasts for photosynthesis
• Vascular bundles


  Transport water, minerals, and sugars throughout plants
• Xylem


  Transports water
• Phloem


  Transports food materials
• Spongy mesophyll


  Facilitates gas exchange for photosynthesis
• Chloroplasts


  Produce energy through photosynthesis
• Flat, thin leaves aid in gas exchange and light absorption for photosynthesis
• Respiration


  Occurs in mitochondria
• Photosynthesis


  Occurs in chloroplasts
• Plants need respiration to grow and produce energy
• Test with pondweed


  Demonstrates how light intensity affects photosynthesis
• Observing bubbles of gas from pondweed

  Can indicate the rate of photosynthesis under different light intensities