Ecology Flashcards
What is an ecosystem?
An ecosystem is the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment.
How do organisms survive and reproduce?
organisms require a supply of materials from their surroundings and from the other living organisms there.
What do plants do to reproduce<
Plants in a community or habitat often compete with each other for light and space, and for water and mineral ions from the soil.
What do animals do to reproduce?
Animals often compete with each other for food, mates and territory
Why do all the species depend on each other?
If one species is removed it can affect the whole community. This is called interdependence. A stable community is one where all the species and environmental factors are in balance so that population sizes remain fairly constant.
Abiotic (non-living) factors which can affect a community are:
light intensity
* temperature
* moisture levels
* soil pH and mineral content
* wind intensity and direction
* carbon dioxide levels for plants
* oxygen levels for aquatic animals.
Biotic (living) factors which can affect a community are:
- availability of food
- new predators arriving
- new pathogens
- one species outcompeting another so the numbers are no
longer sufficient to breed.
how organisms are adapted to
live in their natural environment
Organisms have features (adaptations) that enable them to survive in the conditions in which they normally live. These adaptations may be structural, behavioural or functional.
What are extremophiles?
Some organisms live in environments that are very extreme, such as at high temperature, pressure, or salt concentration. These organisms are called extremophiles. Bacteria living in deep sea vents are extremophiles.
Explain how the food chains work:
photosynthetic organisms are the producers of biomass for life on Earth. Feeding relationships within a community can be represented by food chains. All food chains begin with a producer which synthesises molecules. This is usually a green plant or alga which
makes glucose by photosynthesis.
what is the order of the food chain:
Producers are eaten by primary consumers, which in turn may be eaten by secondary consumers and then tertiary consumers.
What happens in the carbon cycle?
The carbon cycle returns carbon from organisms to the atmosphere as carbon dioxide to be used by plants in photosynthesis.
What does the water cycle do?
The water cycle provides fresh water for plants and animals on land before draining into the seas. Water is continuously evaporated and precipitated.
What is biodiversity?
Biodiversity is the variety of all the different species of organisms on earth, or within an ecosystem.
What does biodiversity ensure?
A great biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment.
