Ecology- Biology

• An ecosystem is the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment.
• Organisms need things from their environment and from other organisms in order to survive and reproduce.
• Habitat is the place where an organism lives
• Population is all the organisms of one species living in a habitat
• Community is the population of different species living in a habitat.
• Abiotic factors are non-living factors of the environment- temperature
• Biotic factors are the living factors of the environment like food
• Plants in a community or habitat compete for light and space as well as water and mineral ions from the soil
• Animals compete with each other for food, mates and territory
• Organisms compete with different species for the same resources
• Interdependence is when each species depend on other species for food, shelter, pollination, seed dispersal etc. If one species is removed it can affect the whole community.
• A stable community is one where all the species and environment factors are in balance so population sizes remain fairly constant
• Examples of abiotic factors include: moisture level, light intensity, temperature, carbon dioxide levels (plants), wind intensity and direction, oxygen levels and soil pH and mineral content
• Examples of biotic factors include: new predators, competition, new pathogens and availability of food.
• structural adaptations

  organisms body structure- shape or colour. camouflage- white fox. blubber- retain heat. thin layer of fat- lose heat
• behavioural adaptations


  ways organisms behave. migrate in winter to warmer climates
• functional adaptations

  inside organisms body related to processes like metabolism or respiration. desert animals don't sweat to conserve water. brown bears hibernate over winter- lower metabolism to conserve energy
• extremophiles

  adapted to live in very extreme conditions. high temps, high salt concentrations etc
• producers

  make food via photosynthesis. start of every food chain.
• biomass

  mass of living material in an organism or group of organisms. energy stored
• environmental changes can cause the distribution of organisms to change.
• availability of water

  -distribution of some animals and plants change in the tropics between wet and dry seasons. more rainfall, more water available.
• temperature changes


  rise in temperature can cause species to move to an area, whereas a decrease can cause them to move out of the area
• atmospheric gases

  more air pollution- some can't survive.
• environmental changes affecting distribution of organisms can be caused by seasonal factors, geographical factors or human interaction.
• water cycle

  -energy form sun makes water evaporate. water vapour. transpiration

  -rises. cools and condenses to form clouds.

  -precipitation- fresh water for animals and plants.

  -drains to sea and begins again
• factors that affect decay

  temperature, oxygen availability, water availability, number of decay organisms
• temperature- decay

  warmer- increase decay as it increases rate at which the enzymes work at. too hot- enzymes denature- organisms die. cold slows down the rate.
• oxygen- decay

  need oxygen to respire. microorganisms in anaerobic decay don't need oxygen
• water- decay

  moist environments- happens quicker because microorganisms need water to carry out biological processes
• number of decay organisms- decay

  more microorganisms, faster decay
• batch generators

  small batches. manually loaded with waste. by products cleared away after every session
• continuous generators

  waste continuously fed in and biogas produced at steady rate. large scale
• bio gas generators need

  -inlet for waste material to be put in

  -outlet for digested material

  -outlet so biogas can be piped to where its needed
• biodiversity is the variety of different species of organisms on earth or within an ecosystem
• high biodiversity is important as it makes sure that ecosystems are stable. different species rely on each other for different things.
• deforestation, waste production and global warming are reducing biodiversity
• larger amount of humans means a larger effect on animal and plant populations and the environment
• increasing population puts pressure on the environment- need resources.
• humans demand a higher standard of living so use raw materials but also need energy to manufacture things. this means we are taking resources from the natural environment. may run out