7. AQA GCSE Biology: Ecology
... methods must be found to feed all people on Earth - ANS-Sustainable
\A protein-rich food suitable for vegetarians - ANS-Mycoprotein
\Abiotic factors - ANS-Non-living factors
\Adaptations - ANS-Features which enable an organism to survive in the conditions in which
they normally live
\Adaptations may be... - ANS-...structural, functional or behavioural
\Apex predators - ANS-Carnivores with no predators
\Biodiversity - ANS-The variety of all the different species of organisms on earth, or within an
ecosystem
\Biological factors which are threatening food security - ANS-BEDPAC
1. Increasing birth rate - in some countries
2. Environmental changes that affect food production - e.g. widespread famine in some
countries if rains fail
3. Changing diets in developed countries - scarce food resources transported around the
world
4. New pests and pathogens that affect farming
5. Cost of agricultural inputs
6. Conflicts -have arisen in some parts of the world which affect the availability of water or
food
\Biotic factors - ANS-Living factors
\Changes as a result of human interaction - ANS-1. Global warming and climate change -
now working to maintain rainforest
2. Acid rain - now reducing water pollution and monitoring pH
3. Pollution from farms and factories - now conservation measures such as replanting
hedgerows and woodlands, restricting access to sites of special scientific interest
\Competition - ANS-The process by which living organisms compete with each other for
limited resources (such as food, light or reproductive partners)
\Describe an experiment to investigate the effect of temperature on the rate of decay of fresh
milk using pH. - ANS-1. Pour fresh milk into 4 different beakers
2. Place 1 in a fridge, 1 at room temperature and 1 in an incubator at 45 degrees C
3. Wait 30 mins for milk to equilibrate (become same temp) then measure the temp with a
thermometer
4. Data collected using a PH logger
5. Measure temperature 2 more times over different days and take a mean
CONTROL: volume of milk, type of milk, time left for, oxygen
SAFETY: hazard of pathogenic growth so swear plastic gloves
\Describe global warming - ANS-1. CO2 and methane contribute to the greenhouse effect -
they absorb some of the Sun's energy which is reflected off the earth
2. However now levels of carbon dioxide and methane in the atmosphere are increasing,
and contribute to 'global warming'
\Describe programmes put in place to reduce the negative effects of humans on ecosystems
and biodiversity - ANS-1. Breeding programmes for endangered species
2. Protection and regeneration of rare habitats
, 3. Reintroduction of field margins and hedgerows in agricultural areas where farmers grow
only one type of crop
4. Reduction of deforestation and CO2 emissions by some governments
5. Recycling resources rather than dumping waste in landfill
\Describe some of the biological consequences of global warming (4) - ANS-1. Loss of
habitats - due to rising sea levels
2. Changes in distribution - as temperatures and rain patterns change
3. Changes in migration patterns - as climates become hotter or colder
4. Reduced biodiversity - some animals will be able to survive as the climate changes eg
polar bears
\Describe the 4 trophic levels - ANS-Level 1. Producers - plants and algae make their own
food
Level 2. Primary consumers - herbivores eat plants/algae
Level 3. Secondary consumers - carnivores eat herbivores
Level 4. Tertiary consumers - carnivores eat other carnivores
\Describe the carbon cycle - ANS-1. CO2 is returned to the atmosphere and dissolved in
water by: combustion of: organic compounds in consumers and dead organisms, fossil fuels;
respiration
2. Photosynthesis removes carbon from the atmosphere
3. Animals eat plants or the plants die & decay
4. Back to the start!
\Describe the nutrient cycle (decay) (6) - ANS-1. Decay starts after death of organism
2. Detritus feeders eat the deceased body and produce waste
3. Decomposers digest everything
4. Decomposers multiply rapidly
5. Waste from decomposers inluding water, CO2 and mineral ions are used by plants to
grow
6. Plants take up mineral ions via roots to make proteins and chemicals in their cells
\Describe the structure of food chains, giving examples. (3) - ANS-1. All food chains begin
with a producer which synthesises molecules e.g. green plants, algae, which make glucose
by photosynthesis
2. Primary consumers eat producers
3. In turn these may be eaten by secondary and then tertiary consumers
\Describe the water cycle - ANS-1. Evaporation: water evaporates from the surface of land
and bodies of water
2. Transpiration: loss of water vapour from plants directly into the atmosphere
3. Respiration: loss of water vapour from animals directly into the atmosphere
4. Condensation: it rises into the air and condenses to form clouds
5. Precipitation: water droplets in clouds get heavier and fall as rain, snow or hail
\Detritivores - ANS-Detritivores/detritus feeders e.g. maggots and flies feed on dead, rotting
material. They break up the dead organism into smaller pieces, increasing the surface area
for digestion by microorganisms.
\Ecosystem - ANS-The interaction of a community of living organisms with the non-living
parts of their environment
\Environmental changes affect... - ANS-...the distribution of species in an ecosystem
\Ethical objections to modern intensive farming methods - ANS-1. Intensively farmed animals
suffer in uncomfortable conditions
2. They are not kept in their natural habitat
... methods must be found to feed all people on Earth - ANS-Sustainable
\A protein-rich food suitable for vegetarians - ANS-Mycoprotein
\Abiotic factors - ANS-Non-living factors
\Adaptations - ANS-Features which enable an organism to survive in the conditions in which
they normally live
\Adaptations may be... - ANS-...structural, functional or behavioural
\Apex predators - ANS-Carnivores with no predators
\Biodiversity - ANS-The variety of all the different species of organisms on earth, or within an
ecosystem
\Biological factors which are threatening food security - ANS-BEDPAC
1. Increasing birth rate - in some countries
2. Environmental changes that affect food production - e.g. widespread famine in some
countries if rains fail
3. Changing diets in developed countries - scarce food resources transported around the
world
4. New pests and pathogens that affect farming
5. Cost of agricultural inputs
6. Conflicts -have arisen in some parts of the world which affect the availability of water or
food
\Biotic factors - ANS-Living factors
\Changes as a result of human interaction - ANS-1. Global warming and climate change -
now working to maintain rainforest
2. Acid rain - now reducing water pollution and monitoring pH
3. Pollution from farms and factories - now conservation measures such as replanting
hedgerows and woodlands, restricting access to sites of special scientific interest
\Competition - ANS-The process by which living organisms compete with each other for
limited resources (such as food, light or reproductive partners)
\Describe an experiment to investigate the effect of temperature on the rate of decay of fresh
milk using pH. - ANS-1. Pour fresh milk into 4 different beakers
2. Place 1 in a fridge, 1 at room temperature and 1 in an incubator at 45 degrees C
3. Wait 30 mins for milk to equilibrate (become same temp) then measure the temp with a
thermometer
4. Data collected using a PH logger
5. Measure temperature 2 more times over different days and take a mean
CONTROL: volume of milk, type of milk, time left for, oxygen
SAFETY: hazard of pathogenic growth so swear plastic gloves
\Describe global warming - ANS-1. CO2 and methane contribute to the greenhouse effect -
they absorb some of the Sun's energy which is reflected off the earth
2. However now levels of carbon dioxide and methane in the atmosphere are increasing,
and contribute to 'global warming'
\Describe programmes put in place to reduce the negative effects of humans on ecosystems
and biodiversity - ANS-1. Breeding programmes for endangered species
2. Protection and regeneration of rare habitats
, 3. Reintroduction of field margins and hedgerows in agricultural areas where farmers grow
only one type of crop
4. Reduction of deforestation and CO2 emissions by some governments
5. Recycling resources rather than dumping waste in landfill
\Describe some of the biological consequences of global warming (4) - ANS-1. Loss of
habitats - due to rising sea levels
2. Changes in distribution - as temperatures and rain patterns change
3. Changes in migration patterns - as climates become hotter or colder
4. Reduced biodiversity - some animals will be able to survive as the climate changes eg
polar bears
\Describe the 4 trophic levels - ANS-Level 1. Producers - plants and algae make their own
food
Level 2. Primary consumers - herbivores eat plants/algae
Level 3. Secondary consumers - carnivores eat herbivores
Level 4. Tertiary consumers - carnivores eat other carnivores
\Describe the carbon cycle - ANS-1. CO2 is returned to the atmosphere and dissolved in
water by: combustion of: organic compounds in consumers and dead organisms, fossil fuels;
respiration
2. Photosynthesis removes carbon from the atmosphere
3. Animals eat plants or the plants die & decay
4. Back to the start!
\Describe the nutrient cycle (decay) (6) - ANS-1. Decay starts after death of organism
2. Detritus feeders eat the deceased body and produce waste
3. Decomposers digest everything
4. Decomposers multiply rapidly
5. Waste from decomposers inluding water, CO2 and mineral ions are used by plants to
grow
6. Plants take up mineral ions via roots to make proteins and chemicals in their cells
\Describe the structure of food chains, giving examples. (3) - ANS-1. All food chains begin
with a producer which synthesises molecules e.g. green plants, algae, which make glucose
by photosynthesis
2. Primary consumers eat producers
3. In turn these may be eaten by secondary and then tertiary consumers
\Describe the water cycle - ANS-1. Evaporation: water evaporates from the surface of land
and bodies of water
2. Transpiration: loss of water vapour from plants directly into the atmosphere
3. Respiration: loss of water vapour from animals directly into the atmosphere
4. Condensation: it rises into the air and condenses to form clouds
5. Precipitation: water droplets in clouds get heavier and fall as rain, snow or hail
\Detritivores - ANS-Detritivores/detritus feeders e.g. maggots and flies feed on dead, rotting
material. They break up the dead organism into smaller pieces, increasing the surface area
for digestion by microorganisms.
\Ecosystem - ANS-The interaction of a community of living organisms with the non-living
parts of their environment
\Environmental changes affect... - ANS-...the distribution of species in an ecosystem
\Ethical objections to modern intensive farming methods - ANS-1. Intensively farmed animals
suffer in uncomfortable conditions
2. They are not kept in their natural habitat
