Ecology

• Habitat: where an organism lives

  Population: all organisms of a species living in a habitat

  Community: populations of different species living together in a habitat

  Ecosystem: interaction of a community between living and non-living parts in their environment
• Competition: struggle for resources

  eg: animals compete for mates, food + water, territory

  plants compete for space, light, water
• Interdependence: all species depend on other species in some way

  eg: food webs
• Structural adaptation (physical appearance):

  
  

  eg - seals are round as they live in cold environments, need store of fat and low surface area:volume ratio to conserve body heat
• Behavioural adaptation:

  eg: migration to warmer areas with more food

  eg: adapted to eat range of food
• Functional adaptation (process in body):

  eg: dessert animals rarely sweat to conserve water

  eg: camel humps of fat break down to release water
• Extremophiles: organisms living in extreme conditions

  eg: salty, temperature, pressure
• Abiotic factors: non-living things that affect the ecosystem eg climate, soil type, pH
• Biotic factors: living things that affect the ecosystem eg predators, prey, pathogens
• Higher trophic levels receive less energy as it decreases when it gets passed down the food chain
• Food chain


  • shows what gets eaten by what in an ecosystem
  • shows transfer of energy
• Producer → primary consumer → secondary consumer → tertiary consumer
• Predator prey cycles have a time lag as the prey population needs to increase before the predator population can increase so there is food for predators

  
• There are always less predators than prey

  • if there were more predators, the prey would go extinct and the predators would starve and then go extinct