Biology Y9 B1

Subdecks (1)

Cards (69)

  • Nucleus
    Control centre
  • Cell membrane
    Controls what goes what goes in and out
  • Mitochondria
    Power house - energy production
  • Cytoplasm
    Where reactions occur
  • Cell wall
    Provides support
  • Chloroplast
    Contains Chlorophyll
  • Vacuole
    Contains cell sap
  • Chloroplasts in the upper epidermis
  • All of the energy that flows through food chains comes originally from the sun
  • Arrows in food chains show what eats what
  • The arrows show the flow of energy through the system
  • What the arrows represent in a food chain

    The flow of energy from one organism to another
  • Trophic level

    Each feeding level in a food chain
  • Trophic levels
    • Producer
    • Primary consumer
    • Secondary consumer
    • Tertiary consumer
  • Keywords
    • Plants
    • Animals
    • Fungi/Bacteria
    • Decomposers
  • Producers
    They produce their own food using carbon dioxide and water
  • Consumers
    Things that eat other living things (can be herbivores, omnivores or carnivores)
  • Herbivore
    An animal that feeds on plants
  • Carnivore
    An animal that feeds on other animals
  • Omnivore
    An animal that eats both plants and animals
  • Ecologists have calculated only 10% of energy available in a trophic level is taken up by the level after
  • Energy flow in a food chain
    1. Sun
    2. Producer
    3. Primary consumer
    4. Secondary consumer
    5. Tertiary consumer
    • 98% energy lost from sun to producer
    • 90% energy lost from producer to primary consumer
    • 90% energy lost from primary consumer to secondary consumer
    • 90% energy lost from secondary consumer to tertiary consumer
  • Why only THREE consumers in the chain?
  • Biomass
    The total mass of an organism
  • How is the energy from food used by organisms?
    • Movement
    • Nutrition
    • Excretion
    • Reproduction
    • Growth
    • Sensitivity
    • Respiration
    • Maintenance of body temperature
  • Energy from cellular respiration is transferred by heating the surroundings
  • Food pyramid
    Each trophic level is represented by a horizontal bar, with the base representing the producer
  • Pyramid of energy
    The width of the bar represents the amount of energy available at each level in the food chain, measured over a period of time
  • Most food chains only have a few links because energy is lost at each level, for example as heat, for movement, and in urine and faeces
  • Energy flow through producers
    1. Most of the sunlight that falls on leaves is not absorbed and used
    2. The overall efficiency of energy transfer during photosynthesis is less than 10%
    3. Only about 1 - 5% of sunlight energy reaching the plant is transferred into useful chemical energy in the carbohydrates
  • Only about 10% of energy is transferred to the next trophic level
  • How energy is lost along the food chain

    • Escapes as heat in respiration to the surroundings
    • Some parts of the plant is not eaten e.g. roots
    • Some parts of the organism is not eaten/digested e.g. fur, teeth, bone, claws
    • Some materials are not absorbed and are egested e.g. urine, faeces
    • Organism uses the energy to stay alive
    • When organism die- energy is 'locked up' which transfers to decomposers
  • Eating meat is wasteful in terms of food energy
  • Food web
    A series of food chains all connected to each other
  • Food webs are easily unbalanced if one population of organisms in the web disappears due to over-predation or hunting, disease, pollution, use of pesticides, lack of food, or emigration
  • Terrestrial, marine, and freshwater food webs are examples of ecosystems
  • Quadrats
    Tools biologists use to estimate the number of plants in an area
  • Sampling

    Taking small samples to investigate distribution of organisms in a large area
  • Distribution
    The way living things are spread out in their habitat