Ecology

• Ecology is

  the study of the world around us

  Interactions between the living and non-living parts of the environment
• Food chains

  Diagrams that help us see the feeding relationships between organisms
• Food chains work from

  left to right
• Food chains start with

  a producer usually a plant
• Arrows show

  the direction of energy transfer
• Each level in a food chain is known as

  a trophic level
• Trophic levels

  Producer

  Primary consumer herbivore

  Secondary consumer carnivore

  Tertiary consumer top carnivore

  Quaternary consumer top carnivore
• How does photosynthesis kickstart energy transfer?

  It takes light energy from the sun and turns it into chemical energy in the glucose that is created

  When a herbivore eats the plant with glucose they use it to release energy in respiration
• Why does energy in a food chain decrease as you go along?

  Energy is used up by organisms as they grow, move and reproduce

  Energy is lost as heat during respiration
• Top carnivores have more than one source of food to

  Get more energy from some than others
• A food web shows us

  The feeding interactions between organisms that live in the same habitat

  Work from top to bottom of page
• A pyramid of numbers shows

  The number of organisms in a trophic level
• A pyramid of biomass shows

  Represents the dry mass of living tissue in the organisms concerned
• Decay

  Dead organisms must be broken down into smaller pieces

  Provides a larger surface area for the decomposers

  Detritivores eg earthworms , woodlice
• Decomposition

  Takes place after decay

  Fungi and bacteria

  Breaks down the organic carbon compounds like proteins and carbs into their simplest components

  These can then be absorbed by plants from the soil

  Humus is the organic content of the soil formed

  Takes place more quickly when conditions are optimum