Flashcards in Ecology Deck (68):
What is a habitat?
The place where an organism lives
What is a population
All the organisms of one species living in a habitat
What is a community?
The populations of different species living in a habitat
What are abiotic factors?
Non-living factors of the environment
What are biotic factors?
Living factors of the environment
What is an ecosystem?
The interaction of a community of living organisms with the non-living parts of their environment
What do plants compete for?
Light, space, water and mineral ions
What do animals compete for?
Space (territory), food, water and mates
What is interdependence?
Where in a community, each species depend on each other for things like food, shelter, pollination and seed dispersal
What is a stable community?
Where in a community, all the species and environmental factors are in balance so that the population sizes are roughly constant
List examples of abiotic factors
Moisture level, light intensity, temperature, carbon dioxide level, wind intensity or direction, oxygen level, soil pH and mineral content
How changes to the environment affect a community?
These can affect the sizes of a population in a community, meaning they can affect the population sizes of other organisms that depend on them; this has knock-on effects because of interdependence
List examples of biotic factors
New predators, competition (one species may outcompete another so that numbers are too low to breed), new pathogens and availability of food
What are the three types of adaptations?
Structural, behavioural and functional
What is a structural adaptation (give an example)?
Features of an organisms' body structure like shape and colour e.g. arctic foxes have white fur which allows them to be camouflaged in the snow
What is a behavioural adaptation?
The way that an organism behaves - many species migrate to warmer climates during the winter to avoid the problems of living in a cold condition
What is a functional adaptation (give an example)?
Things that go on inside an organism's body that can be related to processes like reproduction and metabolism e.g. when brown bears hibernate over winter, they lower their metabolism to conserve energy
What is an extremophile?
Microorganisms that are adapted to live in very extreme conditions, such as high temperatures, high salt concentrations and high pressures
What is a producer?
Always at the start of a food chain, make their own energy with photosynthesis, normally green plants or algae
What is biomass?
The mass of living materials with biological molecules
Give an example of a food chain
Producer --> primary consumer --> secondary consumer
e.g. 5000 dandelions --> 100 rabbits --> 1 fox
How do populations of predators and prey go in cycles?
If the number of prey increase, so will the number of predators but as the number of predators increase, the number of prey will decrease
How can you study the distribution of an organism?
You can measure how common an organism is in two sample areas by using quadrats and them compare them or you can study how the distribution changes across an area by placing quadrats along a transect
How do you estimate the percentage cover of a quadrat?
Especially for a smaller organism, it can be hard to count them individually, so instead count the number of little squares covered by the organism in order to get an estimate
How can a change in the availability of water affect distribution of organisms?
The distribution of some animal and plant species in the tropics changes between the wet and the dry seasons, such as the times of year when there is more or less rainfall
How can a change in temperature affect the distribution of organisms?
E.g. distribution of bird species in Germany is changing because of a rise in average temperature
How can a change in atmospheric gases affect the distribution of organisms?
The distribution of some species change in areas where there is more air pollution e.g. some species of lichen can't grow in areas where sulfur dioxide is given out by industrial processes
What can environmental changes be caused by?
Seasonal factors, geographic factors or human interaction e.g. global warming
Describe the water cycle
Energy from sun evaporates water, vapour is carried upwards, cools and condenses in clouds, water falls from clouds as precipitation.
How are elements cycled through the food chain?
After being passed up the food chain, these materials are returned to the environment through waste products. When the animal dies, it is decayed by microorganisms which put mineral ions back into the soil, which plants use to grow
Describe the carbon cycle
CO2 is taken from the atmosphere by plants, which is released by respiration, eaten by animals which are then decayed and also released by animal respiration, burning of fossil fuels and burning of plants
What is compost?
Decomposed organic matter that is used as a natural fertiliser for crops and garden plants
What is the rate of decay affected by?
Temperature (warmer is quicker due to enzymes), oxygen availability for respiration, water availability for biological processes and number of decay organisms
How is biogas made?
Through anaerobic decay of waste material, mainly producing methane which can be burned as a fuel
How can biogas be made on a large scale?
By using a simple fermenter called a digester or a generator, but they need to be kept at a constant temperature to stop the microorganisms respiring away
What are the two main types of biogas generator and what is the difference between them?
A batch generator which makes biogas in small batches, with manually loaded waste left to digest and continuous generators which make biogas all the time as waste is continuously fed in
What is biodiversity?
The variety of different species of organisms on earth, or within an ecosystem
What human interactions are reducing biodiversity?
Waste production, deforestation and global warming
Why is the world population rising?
Modern medicine and farming methods have reduced the amount of people dying from disease and hunger
How is the increasing human population affecting the environment?
More resources are needed, more raw materials are sues for higher standards of living, more energy is taken for these and raw materials are being used up quicker than they are replaced
How is waste production affecting the environment?
Sewage/toxic chemicals pollute water, affecting plants and animals relying on them, land is affected by herbicides/pesticides, as well as nuclear and household waste and the air is polluted by smoke and acidic gases
How is the earth's temperature increasing?
Gases in the atmosphere act as an insulating layer, by absorbing most of the energy that would normally be radiated back into space and re-radiate it into all directions (including the earth). The increasing amount of these gases in the atmosphere means that the effect is getting out of hand
What are the consequences of global warming?
Seawater expands, ice melts, causing flooding, causing loss of habitats, distribution of organisms will change due to rainfall affected, changes in migration patterns and biodiversity reduced if organisms can not survive climate change
Why are trees chopped down?
To clear land for farming to provide more food and to grow crops from which biofuels based on ethanol can be produced
What problems for the environment can deforestation cause?
Less CO2 is taken in by photosynthesis, more CO2 released from microorganisms feeding on dead wood and from combustion of tree and less biodiversity as less habitats
What is a peat bog?
In bogs (areas of land that are waterlogged and acidic), plants that live there don't fully decay when they die as there is not enough oxygen so they build up to form peat
How can destroying peat bogs add more CO2 to the atmosphere?
The carbon in plants is stored in the peat so when the peat is drained, the microorganisms decompose it, releasing CO2. If the peat is used as fuel, then CO2 is released when it is burnt
What kinds of programmes have been set up to minimise damage done by human activities?
Breeding programmes, protection of habitats, reintroduction of hedgerows and field margins for more organisms, regulation of deforestation and CO2 released and the amount of waste dumped in landfills
Why is it hard to maintain biodiversity?
It costs money, it can come at a cost tot he local people's livelihood, it can harm food security and development of land is seen as important
What does trophic level 1 contain?
Producers which are the starting point of a food chain and produce their own food using photosynthesis
What does trophic level 2 contain?
Primary consumers which are herbivores: their only food source are the plants and algae
What does trophic level 3 contain?
Secondary consumers which are carnivores that eat the primary consumers
What does trophic level 4 contain?
Tertiary consumers which are carnivores that eat other carnivores. They have no predators as they are the top of the food chain, also known as apex predators
What are decomposers?
They decompose any dead plant or animal material left in an environment by secreting enzymes that break the matter down into small soluble food molecules which can diffuse into the microorganisms
What does a pyramid of biomass show?
The relative mass of each trophic level
How do you draw a pyramid of biomass?
The bars must be drawn to scale, the order of organisms in the pyramid must follow the order of the food chain and each bar mus be labelled
How is biomass lost between each trophic level?
Not every part of the organism is eaten (e.g. bones), some is egested as faeces, some is converted into other substances that are lost as waste e.g. glucose to provide energy for moving
How can you calculate the efficiency of biomass transfer between trophic levels?
(biomass transferred to the next level / biomass available at the previous level) x 100
What things can threaten food security?
Population increase, demand for certain food resources, new pests/pathogens, high input costs of farming affects amount of people producing food and conflicts that affect the availability of food and water
How is overfishing decreasing fish stocks?
As we are fishing so much, there is less fish to eat and the ocean's food chains are affected, meaning some species of fish may disappear altogether in some areas
How can fish stocks be maintained?
Fishing quotas, which are limits put on the number and size of fish that can be caught in certain areas and net size limitations which reduces the amount of unwanted and younger fish caught
How can food production be made more efficient?
Livestock can be factory farmed, fish can be factory farmed in cages and some animals can be fed high protein food to increase growth
Why can some factory farming methods be controversial?
People think that making animals like in unnatural and uncomfortable conditions is cruel and as they are kept so close together, disease can spread easily
How can biotechnology be used to produce food sources?
Large amounts of microorganisms can be cultured industrially under controlled conditions in large vats for use as a food source e.g. mycoprotein which is a high protein meat substitutes made from fusarium
How is human insulin made form bacteria?
Plasmid removed from bacterium, human insulin gene taken from human, restriction enzyme cuts it open, human insulin gene is inserted, ligase is added to produce recombinant DNA, inserted into bacterium and grown in vat
What is a restriction enzyme?
They recognise the specific sequence of DNA and cut the DNA at these points. The cut leaves one of the DNA strands with unpaired bases
How can biotechnology help with crop growth?
GM crops can be resistant to pests (increased yield), they can grow better in drought conditions and can have a higher nutritional value