Ecology Flashcards
What are the four levels of organisation within an ecosystem?
- Individual organism
- Population
- Community
- Ecosystem
Define competition in the context of ecology.
Competition occurs when a group of organisms needs the same resource to survive and reproduce, but that resource is limited.
What are the two types of competition?
- Intraspecific competition
- Interspecific competition
What is adaptation in an ecological context?
Adaptation refers to features, behaviours, or characteristics that help an organism survive and reproduce in its habitat.
What is an ecosystem?
An ecosystem is the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment.
Give examples of ecosystems.
- A garden pond
- A woodland
- A coral reef
- A desert
What is interdependence in a community?
Interdependence means each species depends on other species for resources like food, shelter, pollination, and seed dispersal.
True or False: A stable community has all species and environmental factors in balance.
True
What happens to populations if one species is removed from a community?
It can affect the whole community due to interdependence.
What is an abiotic factor?
An abiotic factor is a non-living factor that can affect a community.
Name some abiotic factors that can affect a community.
- Temperature
- Water availability
- Light intensity
- Soil pH
What is a biotic factor?
A biotic factor is a living factor that can affect a community.
Give examples of biotic factors.
- Predators
- Prey
- Competition between species
- Disease
What is the effect of increased CO2 concentration on plant height?
As CO2 concentration increases, average plant height also increases.
What is the relationship between grey squirrels and red squirrels when grey squirrels are introduced into a habitat?
As the number of grey squirrels increases, the number of red squirrels decreases.
What are structural adaptations?
Structural adaptations are physical features of an organism that help it survive in its environment.
What are behavioural adaptations?
Behavioural adaptations are actions or behaviours that organisms perform to survive.
What are functional adaptations?
Functional adaptations are internal processes that help an organism survive.
What adaptations do animals in cold regions have?
- Small surface area : volume ratio
- Thick layer of fat or fur
What adaptations do desert animals have?
- Specially adapted kidneys for water retention
- Activity during cooler times of day
What are extremophiles?
Extremophiles are organisms that can live in extreme environments.
Where can extremophiles be found?
- Deep-sea volcanic vents
- High temperature environments
- High pressure environments
What is the significance of surface area : volume ratios in animal adaptations?
A small surface area : volume ratio reduces heat loss, while a large ratio increases heat loss.
What are photosynthetic organisms known as in an ecosystem?
Producers
They produce their own food using energy from the Sun.
What is the first trophic level in a food chain?
Producer
Producers are always the biggest in a food chain.
What do producers create through photosynthesis?
Glucose
They use glucose to produce other biological molecules.
In extreme environments, what type of producers exist?
Chemoautotrophs
They produce organic molecules without using energy from the Sun.
What is a food chain?
A simple way to show feeding interactions between organisms
It illustrates the transfer of energy from one organism to the next.
What is the role of arrows in a food chain?
They show the transfer of energy
Arrows indicate the direction of energy flow.
What is ecology?
The branch of biology that studies species distribution and interactions
It also includes interactions between species and their abiotic environment.
What tools do ecologists use to determine species distribution?
Quadrats and transects
What are quadrats?
Square frames used to record organisms in a specific area
They can vary in size, such as 0.25m² or 1m².
What does species richness measure?
The total number of different species
It does not count the number of individuals of each species.
How does a transect help in ecological studies?
It measures how species abundance changes across a habitat
Used for assessing factors like altitude or moisture levels.
What factors affect the rate of decay?
Temperature, water, and availability of oxygen
What is decomposition?
The process of breaking down waste products and dead organisms
It is carried out by decomposers like bacteria and fungi.
What is the carbon cycle?
The process of recycling carbon through the ecosystem
It involves photosynthesis, respiration, and decomposition.
What are the main processes of the carbon cycle?
- Photosynthesis by producers
- Feeding by consumers
- Respiration by plants, animals, and decomposers
- Combustion of fossil fuels
What is the water cycle?
The continuous movement of water through various processes
It includes evaporation, condensation, and precipitation.
What role do microorganisms play in ecosystems?
They recycle materials and return carbon and minerals to the environment
Decomposers like bacteria and fungi are crucial for this process.
What is anaerobic decay?
Decay that occurs without oxygen
It produces methane and carbon dioxide.
What is biogas?
Gas produced from anaerobic decay
It consists of methane and carbon dioxide.
What effect does temperature have on the rate of decay?
As temperature increases, the rate of decay increases (up to a point)
What is the aim of RP9 in ecosystem investigations?
To measure the population size of a common species and investigate environmental effects
How can population size be estimated?
By taking random samples within a habitat using quadrats
What does the term ‘predator-prey cycle’ refer to?
The cyclical relationship between predator and prey populations
Predators increase as prey is abundant, then decrease as prey numbers fall.
What are the key patterns in predator-prey cycles?
- Predator numbers increase with prey availability
- Prey numbers decrease as predator numbers rise
- Predator numbers then decrease due to less prey
- Prey numbers increase again as predator numbers decline
What is the significance of compost in gardening?
It acts as a natural fertilizer
Compost is produced from decaying biological material and enriches soil.
What is the purpose of a biogas generator?
To produce biogas from anaerobic decay of waste material
It requires anaerobic conditions and moisture.
What happens to the rate of decay in milk as bacteria run out of sugars?
The rate of decay will decrease
This indicates that bacterial respiration is dependent on the availability of sugars.
How can the rate of decay in milk be calculated?
By measuring pH change per unit time
pH change is an indicator of bacterial activity and decay.
What is the impact of environmental change on species distribution?
It can cause the distribution of living organisms to change
This change can be due to seasonal, geographic, or human-induced factors.
What are some changing environmental factors that affect the distribution of organisms?
- Temperature
- Availability of water
- Composition of atmospheric gases
Each of these factors can significantly influence where organisms are able to thrive.
How do organisms adapt to temperature changes?
They have adaptations that enable them to survive within a certain temperature range
This is crucial for their survival in changing climates.
What effect does climate change have on species distribution in Europe?
Some plant, bird, and insect species are spreading northwards
This is due to higher average temperatures allowing them to inhabit new areas.
Why is water essential for all organisms?
It is essential for biological processes and provides habitat for species
Water supports the growth of plants, which are foundational to food chains.
What migration pattern do wildebeest follow in Africa?
They migrate northwards and then southwards following rainfall
This migration is driven by the search for fresh grazing and water.
What role does oxygen play in the survival of aquatic animals?
It is required for aerobic respiration
Aquatic animals need high oxygen concentrations to survive.
How does pollution affect oxygen levels in freshwater systems?
It encourages the growth of anaerobic microorganisms, leading to a drop in oxygen
This can create conditions where fish cannot survive.
What is required for photosynthesis in plants?
Carbon dioxide
CO2 concentration affects the rate of photosynthesis.
Which species are sensitive to air pollution?
Some species of lichen
They cannot grow in the presence of sulphur dioxide, a pollutant from fossil fuel combustion.
What should you do when evaluating the impact of environmental changes on species distribution?
Reference specific figures from data charts, graphs, or tables
This supports your evaluation with concrete evidence.
What is biodiversity?
Biodiversity is the variety of different species of organisms on Earth, or within an ecosystem.
Why is biodiversity important for ecosystems?
It ensures stability by reducing the dependence of one species on another for food, shelter, and maintenance of the physical environment.
Fill in the blank: A high biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another for _______.
food, shelter, and maintenance of the physical environment.
What are some human activities that reduce biodiversity?
- Producing waste
- Deforestation
- Global warming
What is the impact of human population growth on the environment?
It increases resource consumption, waste production, and pollution.
True or False: Water pollution from sewage and water pollution from fertiliser runoff have the same end result.
True
What is the main reason for habitat destruction?
Increasing human land use for activities such as building, quarrying, farming, and dumping waste.
What are peat bogs?
Areas of land that are waterlogged and acidic, where plant matter accumulates to form peat.
Why are peat bogs important?
- Store carbon
- Provide habitats for many species
What negative impacts result from the destruction of peat bogs?
- Release of carbon dioxide
- Decrease in biodiversity
- Non-renewable energy source
Define deforestation.
The clearing of trees, usually on a large scale.
What are two main reasons for deforestation in tropical areas?
- To provide land for farming
- To grow biofuel crops
What are some consequences of deforestation?
- Extinction of species
- Loss of soil
- Increased carbon dioxide in the atmosphere
What is a greenhouse gas?
A gas that absorbs infrared radiation from the Sun, trapping heat in the Earth’s atmosphere.
List the most important greenhouse gases.
- Water vapour
- Carbon dioxide
- Methane
- Nitrous oxides
- CFCs
What is the greenhouse effect?
The process by which the Sun’s heat is absorbed by greenhouse gases and trapped within the Earth’s atmosphere.
What are some consequences of global warming?
- Ocean temperature increase
- Melting of polar ice caps
- Increased extreme weather events
- Decreases in biodiversity
True or False: Scientists have a consensus that global warming is happening and is largely caused by human activities.
True
What are some conflicting pressures on maintaining biodiversity?
- Cost of conservation programs
- Protecting food security
- Development of society
Fill in the blank: Protecting biodiversity can be very _______.
expensive
What is a common misconception about sewage pollution?
That it causes growth of water plants and algal blooms, which is very rarely the case.
What happens to the carbon that would have been released from decaying plants in peat bogs?
It is stored in the peat.
What do trophic levels describe?
The position of an organism in a food chain, web, or pyramid.
What is the starting point of trophic levels?
Level 1 with plants and algae.
How does energy flow from the Sun in the context of trophic levels?
In the form of light to the first trophic level (producers).
What process do producers use to convert light energy?
Photosynthesis.
What do producers convert during photosynthesis?
Carbon dioxide and water into glucose and oxygen.
What is an apex predator?
A carnivore at the top of the food chain with no predators.
What are the two main groups of decomposers?
- Bacteria
- Fungi
What important function do decomposers perform?
They break down dead plant and animal material.
How do decomposers break down dead matter?
By secreting digestive enzymes onto the surface.
What do decomposers absorb after breaking down dead matter?
Small soluble food molecules.
What nutrients are released back into the environment by decomposers?
Organic nutrients essential for the growth of plants.
What is biomass?
The mass of living tissues or recently dead tissues that have not yet been decomposed.
What is meant by ‘dry mass’ in the context of biomass?
The mass of an organism without including the water content.
How does biomass change as you move up trophic levels?
Biomass decreases.
What shape does a pyramid of biomass take?
Pyramid shape.
What does a pyramid of biomass represent?
The relative biomass at each trophic level in a food chain.
What is the general rule regarding biomass transfer between trophic levels?
Approximately only 10% of the biomass is passed on to the next level.
What are some reasons for loss of biomass at each trophic level?
- Inedible parts of organisms
- Egested material as faeces
- Waste products of respiration and urine
What is the typical maximum number of trophic levels in a food chain?
Rarely more than six.
What is the efficiency of biomass transfers?
The percentage of biomass transferred from one trophic level to the next.
True or False: Organisms can be at different trophic levels in the same food web.
True.
Fill in the blank: Producers use glucose during _______ to produce their own biomass.
respiration
What is food security?
Having enough food to feed a population
This population can range from a family to a country.
What is sustainable food production?
Making enough food without using resources faster than they can be renewed
Resources include water and soils.
How can the efficiency of food production be improved?
By restricting energy transfer from food animals to the environment through:
* Limiting their movement
* Controlling the temperature of their surroundings
What are ethical objections to modern intensive farming methods?
Factory farming is controversial due to:
* Disease spreading easily
* Unnatural and uncomfortable conditions for animals
What is the main cause of declining fish stocks?
Overfishing
What are sustainable fisheries?
Fisheries where the overall population size of fish species does not decrease
The number of fish caught does not exceed the number of new fish born.
What role do fishing quotas play in fish stock conservation?
They limit the number and size of particular fish species that can be caught in a given area
What is biotechnology?
The alteration and use of living organisms to produce products for human use.
What is mycoprotein?
Food created from the fungus Fusarium, suitable for vegetarians
Used in products like QuornTM.
What process is used to produce insulin through genetic engineering?
The gene for human insulin is inserted into bacteria, which then produce insulin.
What are recombinant DNA and genetically modified organisms?
Recombinant DNA is DNA that contains genes from another organism; genetically modified organisms have been altered to contain it.
What is the role of restriction enzymes in genetic modification?
They isolate or ‘cut out’ specific genes, creating ‘sticky ends’ for joining DNA.
What is the purpose of DNA ligase in genetic engineering?
To join two pieces of DNA together to form a single, unbroken molecule.
What are GM crops?
Crops that have been genetically modified for various advantages, such as pest resistance.
What is the benefit of genetically modifying crops to be resistant to herbicides?
Only weeds are killed when herbicides are applied, leaving the crop unharmed.
Fill in the blank: The fungus _______ is cultured to produce mycoprotein.
Fusarium
True or False: Sustainable fisheries contribute to the decline of fish populations.
False
What is the significance of golden rice?
It has been modified to produce vitamin A, helping to prevent deficiency diseases.
What are the advantages of genetically modifying crops to be drought-resistant?
Improves crop yields in dry conditions.
