Flashcards in F215:03:01 Ecosystems Deck (35):
What is an ecosystem?
All living organisms and non-living components in a specific habitat and their interactions
Give an example of a large and small scale ecosystem
Large: African grassland
Define a habitat
a place where an organism lives
Define a population
all of the organisms of one species that live in one place at the same time and can breed together
What is a community?
all the populations of different species that live in the same place at the same time, and can interact with each other
What is a niche?
The role that each species plays in an ecosystem
Why is it almost impossible to define an organisms niche entirely?
Because organisms interact with both living and non-living things
What kind of things are included in a niche?
- How and what an organism feeds on
- What it excretes
- How it reproduces
Is it frequent for two species to occupy exactly the same niche in the same ecosystem?
No, it is impossible
How can living organisms in an ecosystem affect each other?
depending on their niche
Give 5 examples of biotic factors
Give 4 examples of abiotic factors
What is an abiotic factor?
factors that describe the effects of non-living components of an ecosystem
How are ecosystems made easier to understand?
As they are often described as being closed even though they do not have clear edges and it is difficult to draw a line around a group of organisms and say they only interact with each other.
Is population size stable in all ecosystems?
No, the size can rise/fall either very slightly or very noticeably.
Why are their fluctuations of population sizes within ecosystems?
Because the community of living things in an ecosystem interact with each other and with their physical environment.
And so any small changes in one can affect another
How does predators and prey affect each others population size within an ecosystem?
As if a predators population size goes up, then the population size of the prey will go down (because it is being eaten more frequently)
Give an example of how fluctuations in nitrogen levels in soil can alter the population size of plants growing there
Nitrogen-fixing plants would grow more successfully in nitrogen-deficient soil, but they would cause an increase in soil nitrogen levels so then this would help other plants to grow there aswell
How is matter constantly being recycled within an ecosystem and give two examples of this
e.g. nitrogen/carbon cycles
What is constantly recycled within an ecosystem and what is not?
matter is being constantly recycled
Energy is not constantly being recycled, it flows through the ecoystsem
Give an example of how energy flows through living organisms
Energy originates from sunlight
Captured by plant through photosynthesis and converted into chemical energy stored in molecules such as glucose, which are eaten by organisms
In respiration organic molecules e.g. glucose release energy
Give some examples of producers in the food chain
Why are plants, photosyntheic organisms, algae and some bacteria known as producers?
As they supply chemical energy to all other organisms
Give two examples of consumers
Give some examples of primary consumers
give an example of a secondary consumer
carnivores which each herbivores
Give an example of tertiary consumers
Carnivores that eat other carnivores
Give 3 examples of decomposers
Define a decomposer
living things that feed on waste materials/dead organisms
Define a consumer
Living organisms that feed off other living organisms
What is the difference between a consumer and a producer?
A producer is always autotrophic, converting light energy to chemical energy
Consumers gain energy and materials by eating other organisms
What is the difference between a habitat and a niche?
Habitat is where a species lives
a Niche is its role in an ecosystem
Describe the niche of a rabbit that lives in a field
Eats grass in the field
provides waste for decomposers to feed on
hence provides minerals for grass
reproduces with other rabbits
provides food sources for foxes/birds of prey
Suggest why two species never occupy exactly the same ecosystem
If they occupy the same niche, they will compete
One will be better at competing than the other, and will survive and reproduce whereas the other will fail to reproduce and die out.