B4 Ecosystems Flashcards
Define Ecosystem.
All the living organisms and physical conditions in the area.
Define Community.
All of the organisms in the ecosystem.
Define Habitat
Area where an organism lives
Define Consumers.
Organisms that eat others to gain energy.
Define Decomposers.
A special group of consumers that feed on dead or decaying material.
Define Population.
Total number of organisms of each species.
Define Producers.
Organisms that make their own food by photosynthesis.
Define the term ‘interdependence’.
Interdependence relates to living things that rely upon each other to survive.
State four abiotic factors that affect communities.
- Moisture levels – water is required by all living things.
- Temperature – affects the rate of chemical reactions in organisms.
- Light intensity – necessary for photosynthesis. Change in light over seasons can affect flowering of certain plants too.
- Soil type – level of nutrients and ability to hold water, pH.
- Gas levels – humidity and temperature can affect the amount of oxygen in the air.
- Fire – can be devastating for some organisms, but necessary for others (e.g. Australian plants/Scotish gorse/Heathland control).
State four biotic factors that affect communities.
- Number of predators
- Food availability
- Disease
- Human activity
What are the three types of interdependence?
- Predation
- Mutualism
- Parasitism
Define commensalism.
When one organism benefits from another organism, which is unaffected.
Define competition.
When two organisms fight over a resource. Can occur between different species, or within the same species or family.
What is parasitism?
- When one organism lives on or in another organism and takes nutrients from (feeds off) the other organism.
- This is benficial to the parasite but detrimental to the host.
Wht is mutualism?
- When two organisms living closely together both benefit from each other.
- Two organisms that depend on each other