B16 organisms and ecosystems Flashcards
what is the source of energy for most communities of living organisms
light from the sun
what are plants and algae
producers
what is biomass
the mass of one animal or plant species in a food chain or web
what are producers
things that produce there own food from photosynthesis`
how can feeding relationships be presented
food chains
what are primary consumers
animals that eat producers (plants)
examples of primary consumers
sheep, hippos, crabs or caterpillars
what are secondary consumers
animals that eat primary consumers
examples of secondary consumers
lions, foxes, seals or eagles
what are tertiary consumers
animals that eat secondary consumers
what are consumers that eat other animals calles
predators
what are consumers that are eaten called
prey
in a stable community what happens to the levels of predators and prey
they rise and fall in a linked cycle
what are the producers of the biomass for earth
photosynthetic organisms
describe the cycle for predator and prey populations
1 if plenty of food is available prey reproduce successfully so numbers increase
2 As prey numbers go up, predators have more food so their numbers begin to go up
3 the high number of predators eat all the prey leading to prey population falling
4 with less prey, predator numbers begin to drop
5 with less predators, prey numbers go up and the cycle repeats itself.
what are decomposers
a group of organisms that break down waste and dead animals and plants
what chemicals make up organisms
Carbon, Oxygen, Nitrogen and Hydrogen
examples of decomposers
bacteria and fungi
how are organisms decomposed
maggots and worms start the decay cycle by eating dead plants and animals and produce waste material. Bacteria and fungi then digest everything and use the nutrients to release Carbon Dioxide, water and minerals as waste products.
What do decomposes do
clean up the environment
what does decay do
it returns Carbon to the atmosphere.
what are the main stages to the decay cycle
1 plant eaten by consumer
2 death/excretion
3 decomposes break down waste materials and dead bodies
4 Carbon dioxide in air and minerals in soil
5 Carbon dioxide into plants via photosynthesis Minerals into plants through roots
what are the main stages to the water cycle
condensation precipitation evaporation transpiration respiration percolation
what is percolation
where water trickles through gaps in soil and rocks
what is transpiration and respiration
where water gets into atmosphere directly from pants and animals.
what are carbon sinks
a place where carbon is locked up
examples of carbon sinks
coal, oil, gas, dissolved in lakes and oceans
how is Carbon taken out of the environment
photosynthesis
how is carbon returned to the atmosphere
respiration in animals and decomposers
what is combustion
the burning of fossil fuels and wood
how does combustion add carbon to the atmosphere
fossil fuels and wood contain locked up Carbon, and when burnt, this carbon is released back into the atmosphere.
equation for combustion
fossil fuel/wood + oxygen –> Carbon dioxide +water
describe the carbon cycle
- animals eat plants
- animals and plants die leaving organic materials in dead organisms
- decay and decomposition releases co2 into air when decomposers respire
- carbon compounds in fossil fuels are burnt releasing co2 into air
- photosynthesis removes co2 from environment
- respiration from plants and animals returns CO2 to atmosphere
what is causing global warming
levels of carbon dioxide in the atmosphere have increased.
what do scientists fear about the carbon cycle
it may not maintain atmospheric carbon dioxide at a level that will maintain long term human survival
