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AdaptationAdaptation
Organisms are ADAPTED to the habitat they live in. In other words, they have special features that help them to survive. Some examples:
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CompetitionCompetitionAny living species competes with each other. They may compete for:
- Living space
- Food
- WaterIn addition to this competition, the population of a species can be affected by predators, disease, migration etc
Get off my land
Yum!
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Predators and PreyPredators and PreyA PREDATOR is an animal that hunts and eats another animal
The PREY is the animal it eats, for example…
Consider the populations of these two animals over time:
Hey! I ordered a
steak
Population of animal
Time
Rabbit
Fox
Prey Predator
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Food chainsFood chainsA food chain shows where the energy goes in a food chain (in other words, “what gets eaten by what”):
Cabbage
Rabbit Stoat Fox
The arrows indicate where the energy is going
Plants convert the sun’s energy into
food
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Pyramids of biomassPyramids of biomassIn this food chain we can see that the mass of organisms in each stage is less than in the previous stage:
Cabbage
Rabbit Stoat Fox
We can draw a “Pyramid of Biomass” to show this pattern:
Mass of cabbages
Mass of rabbits
Mass of stoats
Mass of foxes
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Energy flow in a food chainEnergy flow in a food chainConsider the energy flow in this food chain:
Cabbage
Rabbit Stoat Fox
100% 10% 1% 0.1%
Clearly, not all of the ___’s energy that becomes stored in the _______ will end up in the fox. Only around ______ is passed on to the next stage in each food chain.
Energy is lost at each stage because of a number of reasons:
1) Each organism has to ____, keep warm etc
2) Energy is lost through faeces (______)Words – 10%, move, sun, waste, lettuce
04/11/23Improving the efficiency of a food Improving the efficiency of a food chainchain
Clearly, food chains aren’t very efficient. How could the efficiency of a food chain be improved?
1) Reduce the number of stages in the chain:
Cabbage
Rabbit Stoat
2) Limit an animal’s movement or keep it warm:
Fox
3) Use plant hormones to regulate the ripening of fruit
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Recycling ourselvesRecycling ourselves
Microbes are the key to this – they break down waste and dead bodies so that the products can be used by plants for growth. Microbes work best in warm, moist conditions where there is plenty of oxygen.
Eating
Waste
Death
Broken
down
Absorption
04/11/23The Carbon The Carbon CycleCycle
CO2 in air 1. CO2 is taken
in by plants for photosynthesis and turned into carbohydrates
2. Plants release CO2 through respiration
3. The carbon taken in by plants is then eaten by animals
5. Animals (and plants) die and their remains are fed on by microbes
6. These microbes also release CO2 through respiration
4. Animals release CO2 through respiration
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The Nitrogen CycleThe Nitrogen Cycle1. Plants absorb nitrogen in the form of NITRATES
2. Plants are then eaten by animals – the nitrogen becomes PROTEIN
3. Microbes break down waste products and dead animals and plants to form AMMONIUM COMPOUNDS
4. Nitrifying bacteria convert ammonium compounds into NITRATES
Nitrates in the soil
Waste and dead animals
Animals
Plants
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Population and PollutionPopulation and Pollution
The human population is growing exponentially:
Population
Time
This has a number of effects on the environment:
Bigger population means…
Building – more
buildings needed
Farming –less land
available for crops
Waste –more waste needs to be disposed of
Quarrying and mining –
raw materials and sources of energy are
being used up
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PollutionPollutionHumans pollute the Earth in a number of ways:
Water – with sewage, fertiliser or toxic chemicals
Air – with smoke or gases such as sulphur dioxide
Land – with toxic chemicals, pesticides and waste
NO, NO2
and CO
Acid rain
Power stations produce CO2, SO2 and NO2
Cars produce NO, NO2 and CO
These gases produce acid rain (which affects tress and buildings) and worsens the greenhouse effect
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The Greenhouse EffectThe Greenhouse EffectWe get heat from the sun:
A lot of this heat is _______ back into space.
However, most of it is kept inside the Earth by a layer of gases that prevent the heat escaping by _______ and then re-radiating it back again.This is called the _________ Effect. It has always been around, but is
currently being made worse due to:
1) Burning (releasing CO2)
2) __________ (removing trees that remove CO2)
3) Increased micro organism activity (from rotting ______)
4) Cattle and rice fields (they both produce _______)
These changes will cause GLOBAL WARMING and RISING SEA LEVELSWords – methane, radiated, absorbing, deforestation, waste, greenhouse
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EutrophicationEutrophicationYet another example of pollution, eutrophication is when lakes become stagnant due to careless use of fertiliser. There are six steps:
1) Inorganic fertilisers used on fields are washed into the lake
3) This growth causes overcrowding and many plants die due to lack of enough light or food
2) The fertiliser causes increased growth in water plants
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EutrophicationEutrophication4) Microorganisms and bacteria increase in number due to the extra dead material
5) These microorganisms use up the oxygen in the lake during respiration
6) The lack of oxygen causes the death of fish and other aquatic animals
Can’t…breathe…
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EutrophicationEutrophication4) Microorganisms and bacteria increase in number due to the extra dead material
5) These microorganisms use up the oxygen in the lake during respiration
6) The lack of oxygen causes the death of fish and other aquatic animals
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Sustainable DevelopmentSustainable DevelopmentSustainable development is all about preserving the world
for tomorrow. There are three main strands:
1) Economic development
2) Social development
3) Environmental protection
Examples of sustainable development include:
1) Replanting trees after chopping them down
2) Limiting the number of fish allowed in a catch
3) Protecting endangered species
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