Question 1
What is meant by a community in ecology?
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All populations living together in a habitat
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All abiotic factors in one ecosystem
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All individuals of one species
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All decomposers in a food web
Question 2
Which is a biotic factor in an ecosystem?
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Competition for food
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Light intensity
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Soil pH
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Temperature
Question 3
Which is an abiotic factor in an ecosystem?
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Moisture level
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Predation
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Disease-causing microorganisms
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Availability of prey species
Question 4
What do decomposer microorganisms do?
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Break down dead material and waste, releasing mineral ions
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Use light to build biomass from carbon dioxide
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Feed on living prey and transfer biomass
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Release nitrogen gas by breaking down nitrates
Question 5
About what percentage of biomass passes to the next trophic level?
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Around \(10\%\)
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Around \(1\%\)
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Around \(50\%\)
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Around \(90\%\)
Question 6
What is a transect used for in ecology?
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To study how organisms change across a habitat gradient
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To identify blood groups in a population
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To separate biotic and abiotic factors chemically
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To measure oxygen uptake in athletes
Question 7
Decay by microorganisms is generally fastest in which conditions?
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Warm, moist and aerobic
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Cold, dry and anaerobic
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Cold, moist and acidic
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Warm, dry and no oxygen
Question 8
In composting, which organisms mainly carry out decomposition?
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Bacteria and fungi
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Red blood cells
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Viruses
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Root hair cells
Question 9
Which gas produced by decomposition in landfill contributes to global warming?
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Methane
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Nitrogen
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Hydrogen
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Oxygen
Question 10
What often triggers eutrophication in freshwater?
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Nitrate and phosphate ions
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Dissolved oxygen
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Glucose and amino acids
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Carbon monoxide and sulfur dioxide
Question 11
How can deforestation reduce biodiversity?
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It removes habitats and food sources for many species
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New forest edges replace the niches that were lost
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Separating populations increases gene flow between them
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A crop monoculture provides a wider range of habitats
Question 12
Which method helps conserve biodiversity?
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Maintaining seed banks and breeding programmes
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Clearing old forests for monoculture farming
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Releasing untreated sewage into rivers
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Increasing landfill use instead of recycling
Question 13
Why is maintaining high biodiversity often linked to ecosystem stability?
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Ecological roles are shared among more species
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Competition between species disappears
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Populations stop changing in size
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Abiotic factors no longer affect the community
Question 14
Why is fish stock management needed in some seas?
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To prevent overfishing and allow populations to recover
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To eliminate predator species
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To raise ocean temperature for faster growth
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To increase eutrophication for plankton blooms
Question 15
Which method records abundance in strips across a habitat gradient?
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Belt transect
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Line transect
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Random quadrat sample
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Mark-release-recapture
Question 16
What is biomass?
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The mass of living material
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The number of species
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The energy in sunlight
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The mass of soil
Question 17
Photosynthesis removes a gas that respiration returns. Which cycle?
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The carbon cycle
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The nitrogen cycle
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The water cycle
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The rock cycle
Question 18
What is eutrophication?
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Nutrient enrichment causing algal growth and oxygen loss
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Toxin build-up at higher trophic levels
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Water acidification by dissolved gases
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Sediment build-up that makes a river shallower
Question 19
What do decomposers release from dead material for plants to absorb?
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Mineral ions
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Whole protein molecules
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Insoluble starch grains
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Atmospheric nitrogen gas
Question 20
What is an indicator species?
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A species whose presence gives information about conditions
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A species used to treat a disease
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A species at the top of every food chain
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A species produced by genetic engineering
Question 21
Which action helps conserve peat bogs?
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Avoid drainage and reduce peat extraction
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Drain channels to increase oxygen in the peat
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Remove peat and replace it with garden compost
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Plant fast-growing trees across the bog
Question 22
What is an organism that lives in very extreme conditions called?
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An extremophile
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A producer
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A decomposer
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A consumer
Question 23
Which fungus is grown to produce mycoprotein?
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Fusarium
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Penicillium
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Yeast
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Rhizopus
Question 24
Which change can alter where a species is found?
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Temperature rising
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Its name changing
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Its class changing
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Its genome shrinking
Question 25
Why are some farm animals kept in small indoor pens?
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To reduce energy lost moving
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To increase their variation
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To speed up their breathing
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To lower their food intake
Question 26
Which factor threatens food security?
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A rising human population
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A falling human population
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Improved crop yields
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Better food storage
Question 27
Which gas contributes most to the enhanced greenhouse effect?
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Carbon dioxide
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Nitrogen gas
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Oxygen gas
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Argon gas
Question 28
What does an arrow in a food chain show?
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The direction energy flows
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Which animal is eaten
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Which animal is fastest
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Where the animals live
Question 29
Which organisms turn nitrogen gas into nitrogen compounds?
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Nitrogen-fixing bacteria
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Decomposers
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Nitrifying bacteria
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Denitrifying bacteria
Question 30
In a pyramid of biomass, what does the width of each bar show?
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The biomass at that level
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The number of organisms
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The energy lost as heat
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The size of each organism
Question 31
Which trophic level number is given to producers?
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Level 1
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Level 2
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Level 3
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Level 0