Food webs Flashcards
What do the arrows represent in food chains?
The arrows in a food chain show the direction of the energy is flowing
What trophic levels make up food chains
- Autotroph
- Hetrotroph
Describe the autotroph level
Autotrophs are capable of synthesizing their own molecules surrounding material, which they have taken in from their surroundings.
Describe the heterotroph level
A heterotroph must digest and break down organic material in order to synthesise the things they need
What is a herbivore
A herbivore eats plants that are rich in complex carbohydrates
What is a carnivore
A carnivore consumes meat that is rich in proteins which are much easier to digest
What is an omnivore
eats plants and animals
What comes first on the food chain
the producer
Where does the energy for food chains come from
the energy for food chains ultimately comes from the sun (photosynthesis)
Is the sun drawn on a food chain
no
What is the order of the food chain
producer > primary consumer > secondary consumer > tertiary consumer
What are the other types of consumers
- scavengers
- detritivores
- decomposers
Describe scavengers
the consumer that feeds on dead and decaying flesh or wastes
Describe detritivores
consume dead organisms and waste
Describe decomposers
Do not ingest food, they secrete enzymes and chemicals onto the food to break it down
What is the 10% rule
The 10% rule in ecology shows that only around 10% of the energy available is passed to the next level
What percentage of energy is egested
10%
What percentage of energy is lost as heat and chemical energy
80%
How much energy do organisms use at each trophic level
At each trophic level, organisms use about 90% of their energy
What percentage of heat energy is lost as chemical energy in waste products
10%
What percentage of energy is available for the next trophic level
Only 10% of the stored energy is available for the next trophic level
What happens when you reach the top consumer in a food chain
By the time you reach the top consumers, there is very little energy left to pass on
What are food webs
In most ecosystems species have more than one feeding relationship. There can be represented in the food web. Food webs are interconnecting food chains
How do ecosystems become unstable
if species are removed
How do ecosystems remain stable
The more feeding relationships (and therefore the greater biodiversity) present in an ecosystem the more stable it will become
