SB9 Flashcards
What is community
All the organisms of different species living in a habitat
What is population
All the organisms of one species in a habitat
What is ecosystem
A community of organisms along with all the non-living conditions
Example of a community
All the living species in a forest
Example of a population
Deer’s in a forest
Example of an ecosystem
All the species and abiotic organisms in a forest
What is interdependence
When organisms depend on each other for things like food and shelter in order to survive and reproduce.
What is mutualism
A relationship between two organisms from which they both benefit.
What are abiotic factors and some examples
Non-living factors that affect communities such as temperature, amount of water, light intensity and levels of pollutants
What are biotic factors and some examples
Living factors that affect communities such as competition and predation
Explain how to estimate population size, including the use of quadrats.
Mean number of organisms per m^2 x area
You could use a belt transects calculate the change across a habitat or just use a quadrat.
Describe the energy transfers that occur between trophic levels.
The energy flows from one trophic level to the next after they are eaten.
Explain how energy is transferred at each trophic level, including making some energy less useful.
Energy decreases as it moves up trophic levels because energy is lost as metabolic heat when the organisms from one trophic level are consumed by organisms from the next level.
Explain how energy transfers limit the length of a food chain.
Each energy transfer is inefficient and looses energy each time therefor making it not sustainable.
Explain how energy transfers determine the shape of pyramids of biomass.
It shows how much the creatures at each level of a food chain would weigh if you put them together. Therefore showing how much energy there is at each stage.
Calculate the efficiency or biomass of energy transfer between trophic levels.
efficiency = energy or biomass transferred to next level / energy or biomass available at previous level x100
Explain how communities are affected by abiotic factors
It affects the distribution and population of a species
Describe how competition can affect communities
This can decrease a population that is unable to gain the resources
Describe how predation can affect
communities.
The prey of the predators might increase if the predators decrease
Explain how predator–prey cycles affect communities.
Predators with more prey.
Prey reduces when there are more predators.
Predators reduces when there is less prey
Explain how the structure of a community can affect biodiversity.
Community’s with higher biodiversity have fewer species that depend on just one other for food ect
What do stonefly larvae and freshwater shrimps show
It indicates the water is clean as they are sensitive to the concentration of dissolved oxygen
What do blood worms and sludge worms show
It indicates a very high level of water pollution as they have adapted to pollution conditions
What do some particular types of lichen show
Lots of lichen especially bushy lichen show good clean air as they are sensitive to the concentration of sulphur dioxide.
What do blackspot fungus show
Clean air as they are sensitive to the concentration of sulphur dioxide.
Advantages of using indicator species as evidence for the level of pollution
Cheap
Simple
Disadvantages of using indicator
species as evidence for the level of pollution.
May be other factors of pollution playing a role in the presence or absence of a species
Better to use non living indicators
Other ways to measure pollution
Dissolved oxygen metres
Electronic meters
What is parasitism
Parasitism is the relationship between a parasite and its host. The parasite benefits by gaining nutrients and/or energy from the host.
Describe how hosts are harmed by parasites
The host is harmed by losing energy and/or nutrients.
Examples of parasitism
Head and body lice are passed from people during physical contact
Fleas feed on dogs blood
Plasmodium (malaria) carried by mosquitoes from human to human