CH12: Interactions Within Ecosystems

• What is a habitat?

  It is the place where an organism lives.
• What are Physical Factors of an environment or habitat where an organism lives?

  air, water, temperature, light, mineral content, acidity, alkalinity
• Adaptations in Organisms

  Structural and Behavioural
• What are Behavioural Adaptive Traits?

  The behaviours developed by an organism to allow it to survive in its environment.
• Organisms of the same kind living in the same environment form a population.
• Different populations of organisms living and interacting in a particular environment make up a community.
• The interactions between a community and its physical environment make up an Ecosystem
• Types of Inter-relationships in an Ecosystem

  Predator-Prey

  Mutualism

  Parasitism
• What is Predator-Prey Relationship?

  Predators hunt and kill their preys for food.
• What are the usual adaptive traits of predators?

  • Strong body and great strength
  • Sharp teeth
  • Strong claws
  • High speed
  • Sharp senses for detecting preys
  • Can produce chemicals to lure, paralyse or poison preys
  • Camouflage tactics to deceive or trick the preys
• What are the usual Adaptive Traits of Preys?

  • High speed
  • Small size
  • Effective camouflage
  • Defensive body parts like horns
  • Mimic unpleasant objects to fool their predators
  • Release chemicals to frighten predators off
• What is Mutualism?

  A relationship in which two/more organisms support/benefit one another in a habitat.
• What is Parasitism?

  It is a relationship between a parasitic organism which lives on or in its host organism by benefitting through taking away food and nutrients from the host and eventually causing harm to the host organism.
• Green plants are producers as they are able to carry out photosynthesis in the presence of light with the intake of carbon dioxide and water to manufacture food
• How does energy flow in an ecosystem?

  Through food chains or food webs
• What is a Food Chain?

  It shows the sequence of how energy and nutrients in the form of food is transferred from one organism to another in a habitat.
• What does a food chain consist of?

  Producer

  Primary consumer

  Secondary consumer

  Tertiary consumer
• What is a Food Web?

  It shows how two/more food chains are inter-connected in a habitat.
• At each stage, about 90% of energy is released into the environment as heat energy.
• The last organism in a food chain receives the least amount of energy from the sun.
• Producers absorb light energy from the sun to produce food.
• Consumers obtain energy by feeding on plants or animals, or both.
• Decomposers feed on the remains of dead organisms and faeces
• What is a population? 


  organisms of the same kind living in the same environment
• What is a community?


  Different populations of organisms living and interacting in an environment