Topic 9 Ecosystems Flashcards
What is an ecosystem?
A environment with all biotic and abiotic factors
What is abiotic factor?
Non-living organism
Eg soil
What a biotic factor?
A living organism
Eg animals and plants
What is a population?
All the organisms of a particular species living in the Same area
What is parasitism?
A parasite feeds on another organism while they are living together. This harms the host but benefits the parasite
What is mutualism?
When two organisms live closely together in a way that benefits them both
What are fieldwork techniques?
Quadrats- mean number of organisms in one quadrant x total area/ area of one quadrat
Belt transects- the effect of abiotic and biotic factors on where organisms live can be studied using quadrats
Positives and negatives of fish farming
Positives:
Farming fish reduces fishing of wild fish
Negatives:
Diseases from the farmed fish can spread to wild fish and kill them
What is eutrophication?
Fertilises added to field for crops may get into streams and rivers. This adds nitrates to the water
What are the effects of increasing food demand?
More meat and fish needed which means more land is used for animal farming
New pests and pathogens damaging crops and animals
Increasing waste is produced causing more pollution
What is the carbon cycle?
Burning fossils fuels or combustion releases carbon dioxide
Dead organisms broken down by decomposes form fossil fuels
Respiration in plants and animals and decomposes releases carbon dioxide
During photosynthesis plants and organisms take in carbon dioxide
These plants are eaten by animals so when they die that also releases carbon dioxide
What is the water cycle?
The sea gets heated( evaporation)
Plants and trees respire
Water vapour forms from condensation
The clouds are cooled
The water cools to create precipitation
This water returns to lakes and the sea
What is the nitrogen cycle?
Nitrates in the soil
Breakdown by some bacteria
Nitrogen-fixing by soil bacteria and lightning
Absorption by plant roots (nitrates)
Feed the animals
These animals die
They decompose including soil bacteria
Create ammonia and nitrifying bacteria
