Ecology

    Cards (76)

    • organisms compete for resources to survive
      plants need light and space as well as water and mineral ions
      animals need space, food, water, and mates
      organisms compete with other species for the same resources
    • any change in an environment can have knock-on effects
      species depend on one another for food, shelter, seed dispersal- this is called interdependence
      the interdependence of all living things in an ecosystem mean any major change can have huge effects
      in some communities all the species and environmental factors are in balance so the population sized are roughly constant
    • abiotic factors
      moisture level
      light intensity
      temperature
      carbon dioxide level
      wind intensity and directions
      oxygen levels
      soil pH and mineral content
    • changes in abiotic factors can affect populations
      a change in the environment could be an increase or decrease
      they can affect the population sizes of other organisms that depend on them
      a decrease in light intensity can affect photosynthesis levels with can affect growth levels
    • biotic factors
      new predators
      competition
      new pathogens
      availability of food
    • changes in biotic factors can have knock-on effects

      these changes can affect the sizes of populations in a community which can have knock on effects because of interdependence
      a new predator could decrease numbers in the prey population
    • adaptations allow organisms to survive
      structural
      behavioural
      functional
    • structural
      the features of an organism's body structure- shape or colour
      arctic animals have white fur so they are camouflaged against the snow
    • behavioural
      these are ways an organism behave-many species migrate to warmer climates during the winter to avoid the problems of living in cold conditions
    • functional
      these are things that happen inside an organisms body that can be related to processes like reproduction and metabolism
      desert animals conserve water by producing little sweat and small amounts of concentrated urine
    • microorganisms have a huge variety of adaptations

      some microorganisms are known as EXTREMEOPHILES because they are adapted to extreme environments (high temperatures-volcano)
    • food chains show what is eaten by what in an ecosystem
      they start with a producer- make their own energy- algae
      energy is transferred through living organisms in an ecosystem where organisms eat other organisms
      producer-primary consumer-secondary consumer
    • populations of prey and predators go in cycles
      if the population of prey increases, so will the population of predators, which will decrease the number of prey, decreasing the population of predators, increasing the population of prey
      continuous cycle of fluctuating population levels
    • environmental changes affect the distribution of organisms
      temperature
      availability of water
      composition of atmospheric gases
    • temperature
      the distribution of bird species in germany is changing because of a rise in average temperature
    • availability of water
      the distribution of some plant species in the tropics changes between the wet and dry seasons- the time of year
    • composition of atmospheric gases
      the distribution of some species changes in areas where there is more air pollution
    • the water cycle
      energy from the sun makes water evaporate from the land and sea turning it into water vapour, the warm water is carried upwards and when it gets higher its gets cooler and condenses into clouds, water falls from clouds as precipitation where it provides fresh water for plants and animals where it drains into the sea repeating the process
    • materials are cycled by decay
      living things are made up of materials they take from the world around them, these materials are returned to the environments in waste products or where the organisms die and decay, material decay because they are broken down by microorganisms. this happens faster in warm climates decay puts the stuff that plants need back into the soil
    • the carbon cycle
      co2 is removed from the atmosphere during photosynthesis, the carbon is used to make glucose which can be turned into carbohydrates, fats, and proteins. when plants and algae respire some carbon is returned to the atmosphere as co2, when they are eaten by animals, some carbon is passes up the food chain, those animals then respire. when they die, other animals and microorganisms feed on their remains. these organisms respire animals also produce waste
      carbon is constantly being cycled throughout the environment
    • decomposition can produce compose

      compost is decomposed organic matter that is used as a natural fertiliser for crops and garden plants
      farmers and gardeners try to provide the ideal conditions for quick decay to make compost
    • the rate of decay is affected by factors
      temperature
      water availability
      oxygen availability
      number of decay organisms
    • temperature affects the rate of decay
      warmer temperatures speed up decay because they increase the rate that the enzymes involved in decomposition work at. however if it is too hot decomposition slows down because the enzymes are destroyed
      really cold temperatures slow the rate of decomposition
    • water availability affects the rate of decay
      decay takes place faster is moist environments because the organisms involved in decay need water to carry out biological processes
    • oxygen availability affects the rate of decay
      many organisms need oxygen to respire which they need to do to survive. the microorganisms involved in anaerobic decay do not need oxygen
    • number of decay organisms affect the rate of decay
      the more microorganisms and detritus feeders there are, the faster decomposition happens
    • biogas is mainly made of methane which can be burned as a fuel

      lots of different microorganisms are used to produce biogas. they decay plant and animal waste anaerobically which produces methane gas sludge waste from sewage works or sugar factories is used to make biogas on a large scale biogas is made in a simple fermenter called a digester or generator need to be kept at a constant temperature to keep the microorganisms respiring- biogas cannot be stored as a liquid so has to be used straight away
    • biogas generators
      batch generators
      continuous generators
    • batch generators
      make biogas in small batches. they are manually loaded up with waste, which is left to digest and by-products are cleared away at the end
    • continuous generators
      make biogas all the time. waste is continuously fed in, and biogas is produced at a steady rate. more suited to large-scale biogas projects
    • a biogas generator needs
      an inlet for waste to be put in
      an outlet for the digested material to be removed
      an outlet so the biogas material can be piped where it is needed
    • decay practical
      measure 5cm3 of lipase solution into test tube, measure out 5cm3 of milk and add it to a different test tube, add drops of phenolphthalein indicator to the milk tube, measure 7cm3 of sodium carbonate solution and add it to the tube containing milk it should turn pink, place both tubes into a water bath set to 30C and leave them in- add thermometer add 1 lipase solution to milk tube, start stopwatch, stir the contents, as it loses pink colour record how long took place, repeat at different temperatures and calculate rate of decay
    • biodiversity
      the variety of different species of organisms on earth or within an ecosystem
    • high biodiversity is important

      ensures ecosystems are stable because different species depend on each other for thing like shelter and food, different species can help maintain the right physical environment
    • humans have an increasing effect on the environment
      increasing population puts pressure on the environment as the resources needed to survive are taken
      people around the world are demanding a higher standard of living so more raw materials and more energy is used- more resources
      raw materials are being used quicker than they are being replaced
    • humans are producing more waste- pollution
      water
      land
      air
    • water pollution
      sewage and toxic chemicals from industry can pollute lakes, rivers, and ocean, affecting the plants and animals that live there
      chemicals used on land can be washed into water
    • land pollution
      toxic chemicals are used for farming
      nuclear waste is buried underground and household waste is dumped in landfill sites
    • air pollution
      smoke and acidic gases released into the atmosphere can pollute the air- acid rain is caused by sulphur dioxide
    • carbon dioxide and methane in the atmosphere trap energy from the sun
      gases in the atmosphere act as an insulating layer, they absorb most of the energy that would normally be radiated back into space greenhouse gases in the atmosphere keep energy in- the earth is heating up due to the increase in the amount of greenhouse gases