Ecology Flashcards
What 4 components are ecosystems made up of?
- Producer
- Consumers
- Decomposers
- The physical environment
What are producers?
Plants which photosynthesise to produce food.
What are consumers?
Animals that eat plants or other animals.
What are decomposers?
Organisms that break down dead material and help to recycle nutrients.
What is the physical environment?
All the non-biological components of the ecosystem.
What are biotic components?
The living components of an ecosystem.
What are a abiotic components?
The non-living components of an ecosystem.
What is a habitat?
A place where an organism lives.
What is a population?
All the organisms of a particular species found in an ecosystem at a certain time.
What is a community?
The populations of all species found in an ecosystem at a particular time.
How to place quadrats randomly in an area?
- Generate a pair of random numbers using a calculator.
- Use the numbers as coordinates to position the quadrat in a large square.
What is biodiversity?
- The range and variety of different species of organisms on Earth, or within an ecosystem.
- Also the variation within each species.
Why is biodiversity a good thing for an ecosystem?
- Ecosystems with high biodiversity are more stable.
- Because it is less likely to be affected by an ecological disaster.
Examples of interactions in ecosystems?
- Feeding among the organisms.
- Competition among the organisms.
- Interactions between organisms and the environment.
What is a predator?
An animal that kills and eats other animals.
What is a parasite?
An organism that live in or on another organism and gets its nutrition from the host.
Examples of biotic factors that influence the numbers and distribution of organisms in an ecosystem.
- Availability of food and competition for food.
- Disease.
- Predation.
- Parasitism.
Examples of abiotic factors that influence the numbers and distribution of organisms in an ecosystem.
- Temperature
- Sunlight
- Soil conditions.
- Pollution.
What are biomes?
Large areas of the Earth dominated by a specific type of vegetation.
What is the simplest way of showing feeding relationships within an ecosystem?
A food chain
What does the arrow mean in a food chain?
‘Is eaten by’ and shows the direction of energy flow.
What are trophic levels?
The different stages in a food chain.
What is (dry) biomass?
The total mass of an organism (after water has been removed).
How do you get the dry biomass of an organism?
By drying the animal or plant in an oven.
Why is dry biomass more reliable?
The water contents of organism varies with environmental conditions.
What are ecological pyramids?
Diagrams that represent the relative amounts of organism at each trophic level in a food chain.
What are the two main types of ecological pyramid?
- Pyramids of numbers.
- Pyramids of biomass.
What do pyramids of numbers represent?
The numbers of organisms in each trophic level in food chain.
What do pyramids of biomass represent?
The total mass of the organisms in each trophic level.
Why is there energy loss between the trophic levels?
- Some parts of the food are not eaten.
- Some parts of the food are not digested.
- Some of the materials absorbed form excretory products.
- Many of the materials are respired to release energy, with the loss of carbon dioxide and water.
How much energy entering a trophic level is passed on to the next level?
10%
List the processes which are important in cycling carbon through ecosystems?
- Photosynthesis
- Feeding and assimilation
- Fossilisation
- Combustion
Examples of biological molecules which contain carbon?
- DNA
- Carbohydrates
- Proteins
Examples of biological compounds which contain nitrogen?
- Amino acids
- Proteins
- DNA
List the processes which are important in cycling nitrogen through ecosystems?
- Feeding and assimilation
- Decomposition
- Nitrification
How is decomposition part of the nitrogen cycle?
Decomposition by fungi and bacteria produces ammonia from the nitrogen in compounds like proteins, DNA and vitamins.
What does denitrifying bacteria do?
Uses nitrates as an energy source and converts them into nitrogen gas.
What are humans making increasing demands on the environment for?
- Food
- Materials
- Fuel
- Space to build
- Space for waste
Ways that yield from crops can be improved?
- Fertilisers
- Ploughing fields
- Controlling soil pH
How do greenhouses provide very controlled conditions for plants to grow?
- Transparent walls allow natural light for photosynthesis.
- They provide warmth and humidity to promote growth.
- Additional lighting and heat can be added.
What are the main two types of fertilisers?
- Organic and inorganic.
What are organic fertilisers made from?
Faeces of farm animals mixed with straw.
What are inorganic fertilisers made from?
Inorganic compounds such as potassium nitrate or ammonium nitrate.
What are pests?
Organisms that reduce the yield of crop plans or stock animals.
How can a pest harm crop yield?
- By reducing growth.
- Affecting the appearance or quality of a crop.
How can pests be controlled?
- Pesticides
- Biological control methods
Problems with pesticides?
- A pest may develop resistance to the chemical.
- They can cause environmental damge.
How do pesticides cause environmental damage?
- They kill other insects that are harmless.
- They may be slow to decompose
- They build up in the tissues of organisms.
What is biological control?
Using another organism to reduce the numbers of pests?
Main problem with biological control?
It never fully gets rid of a pest because if it killed all the pests it would die out too.
Advantages of fish farming?
- The water quality can be monitored.
- Some conditions can be modified.
- The diet of the fish is controlled.
Why is fish farming criticised?
- The potential for spread of disease is high.
- Pollution due to the organic material from the animals’ faeces.
Pollution definition?
The contamination of the environment by harmful substances that are produced by the activities of humans.
Examples of polluting gases?
- Carbon dioxide
- Methane
- Carbon monoxide
- Sulphur dioxide
Why has carbon dioxide been rising?
- The increase burning of fossil fuels.
- Deforestation
What is the normal greenhouse effect?
- Short wavelength IR radiation from the sun hits earth.
- Some energy is absorbed and emitted again as long wavelength.
- Some long wavelength IR radiation escapes.
Some long wavelength IR radiation is absorbed by greenhouse gases and re-emitted back to Earth.
Effects of rising temperatures?
- Polar ice caps melt and sea levels rise.
- Change the nature of ecosystems.
- More extreme weather
What are two major pollutants of freshwater?
- Sewage
- Minerals from fertiliser.
What is Eutrophication?
Where large amounts of nutrients enter a body of water. (Organic mineral ions, usually nitrates of phosphates)
What is leaching?
Where nitrate is easily washed out of the soil by rain.
What causes an algal bloom?
The excess mineral ions stimulate the rapid growth of algae.
What does interdependent mean?
- All organisms depend rely on each other
- Changes in one species will impact other species in the food web.
How do food webs not fully represent an ecosystem.
- It does not include information about the abiotic factors.
- Any correct example of an abiotic factor
