GCSE Edexcel Biology - Ecosystems
and material cycles Exam Questions
With Assured Answers
9.1 INDIVIDUAL - ANSA single organism.
9.1 POPULATION - ANSAll the organisms of a species in a habitat.
9.1 COMMUNITY - ANSAll the organisms of different species in a habitat.
9.1 ECOSYSTEM - ANSA community of organisms along with the abiotic conditions of a weather.
9.2 Explain how communities can be affected by abiotic factors, including:
a temperature, light, water, pollutants - ANS- Temperature
- Light (grasses replaced with fungi)
- Water (soil dry and waterlogged, plant population decreases)
- Pollutants
9.2 Explain how communities can be affected by biotic factors, including:
b competition, predation - ANS- Competition (organisms compete with other species for the same
resources)
- Predation
9.3 Describe the importance of interdependence in a community - ANSInterdependence - Organisms
depend on each other for food and shelter to survive and reproduce.
Any changes within the population can cause huge knock-on effects on the rest of the community.
9.4 Describe how the survival of some organisms is dependent on other species, including parasitism
- ANSThe parasite takes what it needs to survive, but the host organisms doesn't benefit.
, e.g - Dogs and flea
9.4 Describe how the survival of some organisms is dependent on other species, including mutualism
- ANSRelationships between two organisms, where both organisms benefit.
e.g - Flowering plants and bees
9.6 Explain how to determine the number of organisms in a given area using raw data from field-
work techniques, including quadrats and belt transects - ANS
9.7B Explain how some energy is transferred to less useful forms at each trophic level and that this
affects the number of organisms at each trophic level, limits the length of a food chain and
determines the shape of a pyramid of biomass in an ecosystem - ANS- Some energy is transferred to
less useful forms at each trophic level.
- This affects the number of organisms at each tropic level and limits the length of a food chain.
- And determines the shape of a pyramid of biomass in an ecosystem.
9.8B Calculate the efficiency of energy transfers between trophic levels and percentage calculations
of biomass - ANS(energy transferred to next level ÷ energy available at previous level) x 100
9.9 Explain the positive and negative human interactions within ecosystems and their impacts on
biodiversity, including:
a fish farming - ANSCan reduce bio-diversity in an area.
- Food added to nets creates a large amount of waste
- They breed many parasites they can kill wild animals.
- Farmed fish can escape the net.
9.9 Explain the positive and negative human interactions within ecosystems and their impacts on
biodiversity, including:
b introduction of non-indigenous species - ANSNon-indigenous increase competition amongst the
indigenous species for resources such as food and shelter, causing a decrease in digenous
populations.
and material cycles Exam Questions
With Assured Answers
9.1 INDIVIDUAL - ANSA single organism.
9.1 POPULATION - ANSAll the organisms of a species in a habitat.
9.1 COMMUNITY - ANSAll the organisms of different species in a habitat.
9.1 ECOSYSTEM - ANSA community of organisms along with the abiotic conditions of a weather.
9.2 Explain how communities can be affected by abiotic factors, including:
a temperature, light, water, pollutants - ANS- Temperature
- Light (grasses replaced with fungi)
- Water (soil dry and waterlogged, plant population decreases)
- Pollutants
9.2 Explain how communities can be affected by biotic factors, including:
b competition, predation - ANS- Competition (organisms compete with other species for the same
resources)
- Predation
9.3 Describe the importance of interdependence in a community - ANSInterdependence - Organisms
depend on each other for food and shelter to survive and reproduce.
Any changes within the population can cause huge knock-on effects on the rest of the community.
9.4 Describe how the survival of some organisms is dependent on other species, including parasitism
- ANSThe parasite takes what it needs to survive, but the host organisms doesn't benefit.
, e.g - Dogs and flea
9.4 Describe how the survival of some organisms is dependent on other species, including mutualism
- ANSRelationships between two organisms, where both organisms benefit.
e.g - Flowering plants and bees
9.6 Explain how to determine the number of organisms in a given area using raw data from field-
work techniques, including quadrats and belt transects - ANS
9.7B Explain how some energy is transferred to less useful forms at each trophic level and that this
affects the number of organisms at each trophic level, limits the length of a food chain and
determines the shape of a pyramid of biomass in an ecosystem - ANS- Some energy is transferred to
less useful forms at each trophic level.
- This affects the number of organisms at each tropic level and limits the length of a food chain.
- And determines the shape of a pyramid of biomass in an ecosystem.
9.8B Calculate the efficiency of energy transfers between trophic levels and percentage calculations
of biomass - ANS(energy transferred to next level ÷ energy available at previous level) x 100
9.9 Explain the positive and negative human interactions within ecosystems and their impacts on
biodiversity, including:
a fish farming - ANSCan reduce bio-diversity in an area.
- Food added to nets creates a large amount of waste
- They breed many parasites they can kill wild animals.
- Farmed fish can escape the net.
9.9 Explain the positive and negative human interactions within ecosystems and their impacts on
biodiversity, including:
b introduction of non-indigenous species - ANSNon-indigenous increase competition amongst the
indigenous species for resources such as food and shelter, causing a decrease in digenous
populations.
