Ecology- Paper 2 Flashcards
Define ‘biodiversity’.
A measure of the variety of all the different species of organisms within an ecosystem
What are two major problems from the exponential increase in human population?
More natural resources are used up, human’s produce more waste, which leadfs to a decrease in biodiversity
State four sources of land pollution.
Human sewage, household wastes, Industrial wastes, pesticides and herbicides in farming
How does land pollution affect biodiversity?
Less (clean) food available / Loss of habitat / Global warming leading to migration
How does human sewage contribute towards land pollution?
Harmful microbes and bad chemicals lead to spread of diseases on land
Explain how household and industrial wastes pollute land.
Take up space in landfills, Toxic or radioactive chemicals which poison soils and desroys habtitats.
State four sources of water pollution.
Untreated sewage, fertilisers, industrial wastes, pesticides and herbicides
Name the situation where a body of water has low oxygen levels, leading to marine organisms’ death.
Eutrophication
What causes eutrophication?
Fertilisers leaked into lakes, excess nutrients causes excessive plant growth, leading to an increase in competition/algae covering water surface (less light allowed into lake for water plants)
What is bioaccumulation?
Accumulation of chemicals in an organism
Name a chemical that gets built up in organisms in bioaccumulation.
Heavy metals/Fertiliers/Pesticides/Herbicides
Why is bioaccumulation bad?
Chemical concentration increases with each trophic level. This may reach fatal levels when they get to the top consumer.
Name a source of air pollution.
Combustion of fossil fuels
How is acid rain formed?
Acidic gases released from burning fossil fuels are dissolved in rain water
Name three acidic gases released from burning fossil fuels.
Carbon dioxide + sulphur dioxide + Nitric oxides
Give 3 effects of acid rain.
Kills plants; Destroys roots in soil; Acidifies bodies of water, killing marine organisms; Affects neighbouring countries; Acid snow kills young plants
What is global dimming?
Particulates made from combustion covers the atmosphere, reflecting sunlight so less light reaches the surface
What causes global dimming?
Particulates
Name two conditions that particulates can cause.
Global dimming + Smog