Interactions with Ecosystems

• Earth provides the environment which we live in. It has

  limited resources.
• As we are closely connected to one another and to the

  environment, our daily actions can impact our environment

  and affect the survival of other living things.
• Conserving the environment means using only the amount of

  Earth’s resources that we need.
• An environment is characterised by physical factors such as air, water, temperature, light intensity, minerals, and pH.
• Organisms that are adapted to their environment have

  higher chances of surviving long enough to reproduce.
• A suitable combination of physical factors allows plants

  to grow, which will in turn provide animals with food and

  shelter. Animals are then able to survive and reproduce.
• Structural Adaptations --> Physical characteristics of an organism that help it to survive in its habitat
• Behavioural Adaptations --> Different behaviours of an organism that allow it to survive in its habitat
• Population --> A group of organisms of the same species living in the same habitat.
• Community --> Different populations of organisms that live and interact with one another in a particular habitat.
• Ecosystem --> The community of living organisms and the physical

  factors with which these organisms interact with
• Predator-prey Relationship:

  • Predators hunt and kill their prey for food.
  • Predators have structural or behavioural adaptations that allow them to hunt successfully, such as sharp teeth, strong claws, high speeds, sharp senses for detecting prey.
  • Prey have adaptations to avoid being caught by their predators, including high speed, small size, camouflage and defensive body parts.
• Mutualism:

  • A relationship in which two or more organisms support or benefit one another.
• Parasitism:

  • A relationship in which one organism, the parasite, benefits at the expense of another, the host.
  • The parasite benefits by obtaining its food or nutrients from the body of its host, which may or may not result in the death of the host.
• When all the interrelationships between organisms in a community are maintained, a stable ecosystem results.
• Changes in environmental conditions or the removal of any organism can disrupt the stability in an ecosystem. This may cause some organisms to decrease in number or even become extinct.
• Green plants are producers. They make food using carbon dioxide and water in the presence of light during photosynthesis.
• Chemical potential energy stored in food molecules is released when the food molecules are broken down by plant cells during respiration.
• Energy released by the plants is used for growth, while some of it is stored within the plants as chemical potential energy.
• Animals are consumers. They are unable to make their own food, but obtain energy and nutrients when they feed on plant or other animals.
• Primary consumers --> Herbivores. They feed directly on plants.
• Secondary consumers --> Carnivores. They eat herbivores.
• Tertiary consumers --> Carnivores. They eat secondary consumers and are the top of the food chain
• Energy gets lost as heat energy, during respiration or in the form of faeces
• Decomposers --> Feed on the remains of dead organisms and

  faeces, breaking them down into simpler substances and nutrients in the process.
• Decomposers activities return nutrients to the environment.
• The flow of nutrients in an ecosystem is cyclical.
• Nutrients

  Substances that organisms need to live, grow, and reproduce; cycled and recycled within an ecosystem through processes like decomposition and nitrogen fixation
• Energy

  The ability to do work; flows through an ecosystem in a linear direction from the sun to producers, herbivores, carnivores, and decomposers; not recycled in an ecosystem