Ecology Flashcards
What size are ecosystems?
They can be either large or small.
What does a well-balanced ecosystem have the potential to do?
It has the potential to be sustainable for long periods of time.
What three things are a must for an ecosystem to be sustainable?
Nutrients, energy, waste detox.
Define a species.
A species is a group of organisms that can interbreed to produce fertile offsprings.
What is a population?
A group of individuals of the same species who live in the same AREA at the same TIME.
If a lion and a tiger can reproduce to make a liger which is fertile, why are they not members of the same species?
They will not interbreed in nature.
What is a community?
A group of populations of different species that live and interact with each other in an area.
What is the study of relationships between living organisms and their environments?
Ecology
What is an ecosystem?
A community of living groups of organisms interacting with its abiotic environment.
What are self-feeders called?
Autotrophs
What kind of nutrients do autotrophs obtain from their environment? What do they build with these nutrients?
Inorganic nutrients, they build organic compounds with these nutrients.
What are some inorganic compounds? How are they maintained?
Phosphorus, carbon, nitrogen which are maintained by nutrient cycling between biotic and abiotic components of the ecosystem.
Where do autotrophs get their energy?
The sun
What returns inorganic building blocks to the environment so that they are available for autotrophs?
Non-consumer heterotrophs such as detrivores and saprotrophs.
What are species that are both heterotrophic and autotropic called?
Mixotrophs
Name a heterotrophic plant.
Orchids
Can organisms exist in more than one feeding level?
Yes.
Is there a maximum number of feeding levels? Why or why not?
There is because energy is limited.
What are chemoautotrophs?
Organisms that make their own food using energy from the chemical bonds of inorganic compounds.
Name a chemoautotroph.
Methanogenic archae
Which trophic level supports all the other levels?
Autotrophs, primary producers
What compound do methanogenic archae use to produce their own food? What chemicals are byproducts of this reaction?
H2S is the compound used and it turns into cglucose and sulfuric acid.
What are primary consumers known as?
Herbivores.
What are three ways to represent energy transfers?
Food chain, food webs, pyramids of energy.
Name two non-consumer heterotrophs. What are the differences between them?
Detritivores= heterotrophs that obtain organic nutrients from detritus by internal digestion. They initiate decomposition into inorganic substances. Saprotrophs= heterotrophs that “putrid feed” and obtain nutrients by external digestion. They finish breakdown.
How do saprotrophs externally digest food?
They secrete digestive enzymes then absorb nutrients.
Name an example of a detritivore. A saprotroph.
ugs and worms are detritivores. Mushroom/fungi are saprotrophs.
What returns energy to the environment?
Nothing.
What are scavengers? Are they decomposers?
Scavengers are animals that feed on recently dead material. They are not decomposers since they eat large amounts.
The quote goes “energy ….. matter…”
Energy flows, mater recycles.
How can energy leave a system?
Can leave as heat or can be used up in biological processes. Can also be stored in indigestible matter.
How much of the incoming solar radiation enters the food chain?
1-2%
How much energy reaches the next tropic level usually?
About 10%
From the lost energy, what can recover some of it?
Saprotrophs/detritivores since they can feed on indigestible matter that is excreted as waste but contains some energy.
What restricts the biomass of higher trophic levels
The fact that energy does not get passed down in its full amount from one level to the next so fewer organisms can be supported.
What are the units of the pyramid of energy?
kJ/m^2/y
What is biomass? Units?
The total dry weight of organisms per sample area. Units are g/m^2
What shape does a pyramid of biomass usually resemble? Why?
A pyramid because of loss of energy, carbon dioxide, water, and other waste products.
When might a pyramid of biomass not resemble a pyramid? Why?
In aquatic ecosystems since autotrophs are being eaten as soon as they reproduce.
What do mesocosms help us investigate?
The sustainablity of an ecosystem.
Are mesocosm closed or open environments? What does that mean?
They are closed which means that there is a fixed supply of matter but energy can come in and out.
What are some advantages of mesocosms?
They are on a smaller scale so cheaper and take less time. Easier to control and manipulate variables without causing irreversible changes to a natral area.
What is a disadvantage to a mesocosm?
They are not realistic and so unforeseen responses are not taken into account.
What is the null hypothesis?
There is no association between species A and B.
When comparing the Chi^2 value to the critical value, what should be observed for the null hypothesis to be accepted?
The chi^2 test must be smaller than the critical value.
Where is carbon found on earth? (6)
sediment/rock, ocean/atmosphere, soil, biomass, methane, peat
What is carbon found in the ocean as?
Dissolved carbon dioxide and hydrogen carbonate ions.
How is methane produced? What organisms make these methane?
By decaying organic and inorganic material where there is a lack of oxygen. Methanogenic archaeans make this.
What is peat? What conditions form it?
Peat is decaying organic material that isn’t fully decomposed in acidic and/or anaerobic conditions in waterlogged soil.
Where does oil, gas and coal come from?
Partially decomposed organic material that has accumulated in porous (spongy) rock.
How are fossils made? What are they? What do they become fossilized as?
Hard parts of animals that are composed of calcium carbonates. They become fossilized as limestone.
How can carbon be released into the environment? (3)
Respiration from animals/plants, methane can be oxidized into Co2 and water, and combustion of organic matter which releases CO2
What is the difference between a carbon sink and source?
A carbon source emits carbon while a carbon sink stores/receives carbon.
What happens to the energy of the sun once it enters the Earth?
A third of it is reflected back while 2/3 of it is absorbed by the earth’s surface.
What hapens to the energy that the earth absorbs from the sun?
It is emitted as long wave radiation (heat).
What can greenhouse gases absorb and retain in the atmosphere? What does this lead to?
Greenhouse gases can absorb long wave radiation and retain it in the atmosphere. This leads to warming.
Name four greenhouse gases.
Water vapour, carbon dioxide, nitrous oxides, methane.
Which two greenhouse gases retain heat the most? Why?
Water vapour and carbon dioxide because of their high concentartion in the atmosphere.
How is carbon dioxide removed from the atmosphere?
By photosynthesis and absorption in the ocean.
Where does water vapour in the atmosphere come from? (4)
Transpiration, evaporation, fossil fuel burning, cell resp.
Where does carbon dioxide in the atmosphere come from? (3)
respiration, fossil fuel burning, teh decay of materials where living or not
Wat is a more effective greenhouse gas than CO2?
Methane
When is methane produced?
When matter decays without the presence of oxygen.
What are some methane sources? (4)
Rice paddies, wetlands, animal digestive processes, fossil fuel extraction, decaying garbage.
Where are nitrous oxides (N2O) from? (2)
Soils and oceans
What causes the production of nitrous oxides? (4)
Soil cultivation, nitrogen fertilizers, nylon production, burning of fossil fuels/organic material.
What are halocarbons effective at doing? Are they responsible for the enhanced greenhouse effect?
Trapping heat, they are greenhouse gases. they are not responsible for the enhanced green house effect.
What do CFCs mainly cause?
Ozone depletion.
Wahat is the sedimentary rock that is dead anaerobic bacteria called?
Stromatolites.
What sign on the stromatolites showed the presence of oxygen and uptake of carbon dioxide in the atmosphere?
Black iron oxide bands in the stromatolites.
Besides an increase in CO2 production, what have humans done to affect the climate? (2)
Change land use like cutting down forests and replacing them with asphalt that increases energy reflected off the earth. Also adding atmospheric aerosols in the air.
What organism can an increase of CO2 in the oceans threaten?
Coral reefs
What can happen to Europe if weather patterns continue to change? Canada?
Europe will cool while Canada will experience great warming.
What are some consequences of rising global temperatures?
Increased rate of decomposition of detritus trapped in permafrost. Loss of habitat. Changes in the distribution of prey species. Increased success of pests. Disruption in ecosystems.
What is the kneeling curve evidence of?
The enhanced greenhouse effect.
Does CO2 naturally increase or decrease in winter? Why?
Increase because there is less photosyntehsis taking place.
What did the kneeling curve observe in the spring? What does that mean?
Spring CO2 declines are starting earlier. This means that seasons are becoming longer.
What is the precautionary principle?
Those responsible for a change must prove that it will not cause harm before proceeding.
