interdependence

• A food chain shows how plants and animals get their energy. It also shows the different species of organisms in an ecosystem, and what eats what.
• Producer

  An organism that makes its own food. Most food chains start with a green plant, because plants can make their food by photosynthesis.
• Consumer


  A living thing that eats other plants and animals
• In Science, we don't draw images to represent food chains, instead we write it using words and arrows
• Predator

  An animal that eats other animals
• Prey

  The animals that predators eat
• Apex predator


  The final consumer at the top of the food chain that is not eaten by anything else
• Trophic levels

  The stages in food chains
• Food web

  When all the food chains in an ecosystem are joined up together
• Types of organisms

  • Herbivores
  • Omnivores
  • Carnivores
• Herbivores only eat plants, omnivores eat both plants and meat, carnivores eat meat
• A food web is made up of different food chains in an ecosystem
• Food chain

  A simplified sequence that shows what eats what in an ecosystem, starting with producers and going to consumers (herbivores, carnivores, omnivores)
• Food web

  Shows how multiple food chains are linked in an ecosystem, demonstrating the flow of energy between different organisms
• Organisms in a food web depend on each other for nutrients. So, a change in one population leads to changes in others. The population of a species is affected by the number of its predators and prey.
• Interdependence


  How different living things rely on each other in an ecosystem to survive and thrive. Changes in one part of the ecosystem can affect other parts.
• Ecosystem


  A community of living organisms (plants, animals, and microorganisms) interacting with each other and their physical environment (like soil, water, and air).
• The flower contains the reproductive organs of a plant. The male sex cell is called pollen and the female sex cell is an egg-called an ovule.
• Parts of a flower

  • Petal
  • Stamen (filament and anther)
  • Carpel (stigma, style, ovary)
  • Receptacle
  • Sepal
• The petal is brightly coloured to attract pollinators such as bees or birds. They may also be scented.
• The flower will contain nectar, a sugary drink for pollinators to drink.
• The stamen is male and is made up of the filament and anther. The anther makes pollen.
• The carpel is female and is made up of the stigma which is sticky and receives pollen, style and ovary, which contains the ovule.
• The sepal is a protective leave when the flower is in a bud.
• Pollination

  The transfer of pollen from the male part of a flower to the female part, which allows plants to reproduce, with bees, butterflies, and other pollinators playing a vital role.
• Once the polen grain lands on the stigma, the DNA moves down through the style into the ovary and into the ovule. The ovule is fertilised and becomes a seed. The ovary swells and becomes a fruit.
• If seeds are found in a plant it is classed as fruit, so things like tomatoes and cucumbers - which contain seeds are in fact classed as fruits.
• Fertilisers


  Chemicals that can help plants to grow faster and bigger, and improve the yield of a crop.
• Fertilisers help plants to grow properly because they contain elements that are essential for their growth, like potassium, phosphorus and nitrogen.
• When plants take up these minerals, fewer are left behind in the soil - fertiliser's help to replace these minerals.
• Pollution

  Harmful substances released into the environment, like factories pumping waste into rivers and seas, oil spills, and emissions from chimneys and vehicle exhausts.
• Bioaccumulation


  The build-up of toxins that cannot be excreted in organisms at the top of the food chain, leading to much higher concentrations and more severe effects.
• Bioconcentration


  The build-up of toxins that cannot be excreted at the tops of food chains.
• DDT is an insecticide that can pass up the food chain from insects to small birds, and then from the small birds to birds of prey, like hawks. It bioconcentrates in the birds of prey because it cannot be excreted.
• Mercury was used until recently to make insecticides and special paints that stop barnacles growing on the hulls of ships. When mercury gets into a food chain, it damages the nervous systems and reproductive systems of mammals, including humans.