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B7 - Ecology - Coggle Diagram
B7 - Ecology
L1 - Ecosystems
A habitat is an area or place in an ecosystem where organisms live.
A community are the animals and plants living within a habitat.
Plants compete for light, space, water and mineral ions. Animals compete for food, mates and territory.
In an ecosystem, organisms are dependent on each other, compete with each other and are adapted to their particular conditions.
Organisms depend on each other for: food, water, mates, shelter, seed dispersal, sun for energy, pollination, oxygen. This is known as interdependence.
In a stable community, all the species and environmental factors are in balance so that population sizes remain constant.
A population is defined as organisms of the same species within an area.
L2 - Adaptations
A structural adaptation is a physical change in response to conditions; examples include wings for flight.
A behavioral adaptation is a change in how an organism acts; examples include hibernation, migration.
A physiological adaptation is involve processes and metabolism; examples include temperature regulation and excretion of toxins.
Organisms that can survive in extreme conditions/environments are known as extremophiles.
Biotic factors living factors in an environment that affect living organisms and the functioning of ecosystems.
Abiotic factors are non living parts of an environment that affect living organisms (light intensity, temp, soil pH)
L8 - Decay Required Practical
Decomposition is vital for recycling material within an ecosystem. The rate of decomposition (by bacteria, fungi or detritus feeders) is affected by several factors:
Moisture
Oxygen levels
Temperature
Number of decay organisms
Temperature affects the rate of decay as chemical reactions occur at a faster rate when temperature is optimum. Moisture affects decay as more moist conditions optimise growth for decay organisms.
Method:
Add a given volume of lipase solution to a boiling tube.
Add a few drops of Cresol red solution to a different test tube labelled "milk".
Using a dropping pipette, add a given volume of milk to the "milk" test tube.
Use a different pipette to add a given volume of sodium carbonate solution. This will turn the solution purple.
Put a thermometer in the "milk" boiling tube.
Set up a water bath at the first temperature.
Wait until the contents reach the same temperature as the water bath.
Use another dropping pipette to transfer a given volume of lipase solution to the "milk" boiling tube and immediately start the stopwatch.
Stir the contents until the solution turns yellow.
Decomposition can produce compost. Farmers try to provide optimum conditions for decay. Compost can be used to provide the land with minerals, aiding plant growth.
Biogas is produced from plant material by bacteria. When bacteria begin to decompose material through anaerobic decay, methane is produced.
L3 - Organisation Levels
All living things need energy to move and grow. A food chain can show us what living things feed on in a particular habitat. These chains begin with a green plant (producer), then a primary consumer...
Decomposers break down dead plant and animal matter by secreting enzymes into the environment.
Pyramids of biomass are constructed to represent the relative amount of biomass in each level of a food chain.
Biomass is the mass of living material in each organism multiplied by the total number of organisms in that trophic level.
L4 - Transfer of Biomass
Not all biomass is transferred from one tropic level to another, this is because:
Not every part of an organism is eaten.
Some consumed biomass is excreted as waste/faeces.
Large amount of biomass are used in respiration (not stored in the organism).
Biomass/energy is lost through heat.
Producer transfer about 1% of the incident energy from light for photosynthesis.
Only 10% of the of the biomass is transferred between trophic levels.
L7 - Population Size Required Practical
Method:
1) Assign a coordinate system to the area you are investigating.
2) Use a random number generator to produce coordinates (this avoids any bias in the investigation).
3) Place a quadrat on the randomly-generated coordinates.
4) Count the number of plants in the quadrat.
5) Repeat this process several times, then calculate an average number of plants.
Biodiversity is a measure of the variety of of different species living in a habitat.
A transect can be used to observe gradual change over a distance. The number of species observed along the transect at given distance intervals.
L10 - Waste Management
Rapid growth of the human population and an increase in the standard of living means that more waste is being produced.
Eutrophication process:
Nutrients from fertilizer enters the water and is used by aquatic plants.
Oxygen is depleted as algae flourishes; also prevents sunlight from reaching aquatic plants.
Plants die and decomposition occurs, depleting oxygen further.
Oxygen levels reach an extreme paucity where no life can thrive so the ecosystem fails.
Humans reduce the land available for plants and animals through building, quarrying, farming and dumping waste. The destruction of peat bogs (used to farm garden compost) decreases the habitat's biodiversity, the decay or combustion of this peat releases CO2.
L11 - Deforestation and Global Warming
Reasons for deforestation include: space for rice fields, land for cattle and the growth of biofuels.
Impacts of deforestation include: more CO2 in the atmosphere, dead vegetation decomposes (releasing CO2).
Global warming occurs when sunlight is reflected off the Earth's surface. Instead of leaving the atmosphere, the light is absorbed by greenhouse gasses in the atmosphere, trapping the energy within the atmosphere and ultimately heating the atmosphere.
L13 - Farming Techniques
Farmers try to maximise the possible increase in biomass from animals efficiently to maximise their profit.
Intensive farming involves animals being packed into enclosed areas where temperature is regulated, this limits movement and therefore the energy expended for respiration but also the energy used in temperature regulation.
Intensive farming has ethical objections concerning animal welfare. It also increases the risk of communicable diseases spreading; henceforth, antibiotics are given to the animals (this increases the potential for resistant strains to develop).
L14 - Biotechnology
Plants can be genetically engineered to be more economical; golden rice is engineered to provide more vitamin A.
Mycoprotein can be farmed from the fungus Fusarium; this is used in making vegetarian 'meat'.
Bacteria can be genetically engineered to produce insulin; this can be used to treat people with diabetes.
L5/L6 - Carbon and Water Cycle
The Water Cycle:
1) Body of water evaporates because the sun.
2) Water vapor condenses into clouds.
3) Precipitation occurs, liquid water seeps into soil and henceforth taken up by plant roots.
4) The cycle repeats.
The Carbon Cycle:
1) Green plants and algae take in carbon dioxide from the atmosphere and convert it into glucose.
2) Some of the carbon is released back into the atmosphere during cellular respiration or into animals (primary consumers).
3) When organisms die, decomposers and detritivores cause decay (microbial respiration occurs or the organism is fossilised).
4) These fossils are then burned by humans, producing carbon dioxide.
L9 - Biodiversity
Biodiversity is the variety of all different species on Earth or in an ecosystem.
Means of maintaining biodiversity include:
Breeding programmes.
Protection of rare habitats.
Reintroduction of field margin and hedgerows.
Recycling resources.
L12 - Food Security
Food security is defined as having enough food to feed the population.
Factors affecting food security include:
Increasing birth rate
Changing diets / obesity in developed countries
New pests and pathogens
Environmental changes
Cost of agricultural
Conflicts / war