Ecology questions

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Ecology question collection

Review Ecology questions for Biology, with correct answers shown and coverage across communities and ecosystems; sampling methods; biodiversity and human impacts.

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Question 1

What is meant by a community in ecology?
  1. All populations living together in a habitat
  2. All abiotic factors in one ecosystem
  3. All individuals of one species
  4. All decomposers in a food web

Question 2

Which is a biotic factor in an ecosystem?
  1. Competition for food
  2. Light intensity
  3. Soil pH
  4. Temperature

Question 3

Which is an abiotic factor in an ecosystem?
  1. Moisture level
  2. Predation
  3. Disease-causing microorganisms
  4. Availability of prey species

Question 4

What do decomposer microorganisms do?
  1. Break down dead material and waste, releasing mineral ions
  2. Use light to build biomass from carbon dioxide
  3. Feed on living prey and transfer biomass
  4. Release nitrogen gas by breaking down nitrates

Question 5

In food chains, about what percentage of biomass is typically transferred to the next trophic level?
  1. Around \(10\%\)
  2. Around \(1\%\)
  3. Around \(50\%\)
  4. Around \(90\%\)

Question 6

Why is only a small fraction of biomass transferred to the next trophic level?
  1. Material is uneaten, excreted or used in respiration
  2. Higher trophic levels contain fewer named species
  3. Consumers store most absorbed material without respiring
  4. Biomass is destroyed when one organism is eaten

Question 7

What is the main purpose of a quadrat in fieldwork?
  1. Estimate abundance or distribution in a sample area
  2. Track the movement of fast animals across a habitat
  3. Measure one abiotic condition at a single point
  4. Count every organism in the whole habitat

Question 8

Why is random sampling used with quadrats?
  1. To reduce sampling bias
  2. To guarantee every species is counted
  3. To increase competition between species
  4. To make decomposition faster

Question 9

What is a transect used for in ecology?
  1. To study how organisms change across a habitat gradient
  2. To identify blood groups in a population
  3. To separate biotic and abiotic factors chemically
  4. To measure oxygen uptake in athletes

Question 10

Decay by microorganisms is generally fastest in which conditions?
  1. Warm, moist and aerobic
  2. Cold, dry and anaerobic
  3. Cold, moist and acidic
  4. Warm, dry and no oxygen

Question 11

What happens to decomposition rate if temperature falls a lot?
  1. It usually decreases
  2. It usually increases sharply
  3. It stays exactly the same
  4. It becomes independent of microorganisms

Question 12

In composting, which organisms mainly carry out decomposition?
  1. Bacteria and fungi
  2. Red blood cells
  3. Viruses
  4. Root hair cells

Question 13

Which gas produced by decomposition in landfill contributes to global warming?
  1. Methane
  2. Nitrogen
  3. Hydrogen
  4. Oxygen

Question 14

What often triggers eutrophication in freshwater?
  1. Nitrate and phosphate ions
  2. Dissolved oxygen
  3. Glucose and amino acids
  4. Carbon monoxide and sulfur dioxide

Question 15

Why can eutrophication kill fish?
  1. Decomposers use dissolved oxygen while breaking down dead algae
  2. Algae use dissolved oxygen while carrying out photosynthesis
  3. Nitrate ions directly block oxygen entering fish gills
  4. Warmer water creates extra dissolved oxygen for decomposers

Question 16

How can deforestation reduce biodiversity?
  1. It removes habitats and food sources for many species
  2. New forest edges replace the niches that were lost
  3. Separating populations increases gene flow between them
  4. A crop monoculture provides a wider range of habitats

Question 17

Why can peat bog destruction increase atmospheric carbon dioxide over time?
  1. Stored carbon is released when peat is drained or burned
  2. Peat bogs absorb no carbon
  3. Peat formation is faster than burning
  4. Carbon dioxide turns into oxygen in dry peat

Question 18

Which method helps conserve biodiversity?
  1. Maintaining seed banks and breeding programmes
  2. Clearing old forests for monoculture farming
  3. Releasing untreated sewage into rivers
  4. Increasing landfill use instead of recycling

Question 19

Why is maintaining high biodiversity often linked to ecosystem stability?
  1. More species make ecosystems more resilient
  2. High biodiversity removes all pathogens
  3. High biodiversity prevents all abiotic stress
  4. High biodiversity means no natural selection

Question 20

Why is fish stock management needed in some seas?
  1. To prevent overfishing and allow populations to recover
  2. To eliminate predator species
  3. To raise ocean temperature for faster growth
  4. To increase eutrophication for plankton blooms

Question 21

How can quadrat data estimate a population across a habitat?
  1. Multiply mean density by the habitat area
  2. Multiply the largest count by the habitat area
  3. Add the quadrat counts without scaling
  4. Use the smallest count as the population

Question 22

Which method records abundance in strips across a habitat gradient?
  1. Belt transect
  2. Line transect
  3. Random quadrat sample
  4. Mark-release-recapture

Question 23

What is biomass?
  1. The mass of living material
  2. The number of species
  3. The energy in sunlight
  4. The mass of soil

Question 24

What is the carbon cycle?
  1. Movement of carbon between organisms and the environment
  2. Movement of oxygen through blood
  3. A method of cell division
  4. A way to classify species

Question 25

How can deforestation affect atmospheric carbon dioxide?
  1. It can increase it by reducing photosynthesis and releasing carbon
  2. It converts carbon dioxide directly to nitrogen
  3. It stops respiration releasing carbon dioxide
  4. It increases photosynthesis in the cleared area

Question 26

What is eutrophication?
  1. Nutrient enrichment causing algal growth and oxygen loss
  2. Toxin build-up at higher trophic levels
  3. Water acidification by dissolved gases
  4. Sediment build-up that makes a river shallower

Question 27

How can captive breeding conserve an endangered species?
  1. Breed individuals and reintroduce their offspring
  2. Breed closely related individuals for many generations
  3. Release offspring before their habitat is protected
  4. Choose breeding pairs only for similar appearance

Question 28

What do decomposers release from dead material for plants to absorb?
  1. Mineral ions
  2. Whole protein molecules
  3. Insoluble starch grains
  4. Atmospheric nitrogen gas

Question 29

What is an indicator species?
  1. A species whose presence gives information about conditions
  2. A species used to treat a disease
  3. A species at the top of every food chain
  4. A species produced by genetic engineering

Question 30

Which action helps conserve peat bogs?
  1. Avoid drainage and reduce peat extraction
  2. Drain channels to increase oxygen in the peat
  3. Remove peat and replace it with garden compost
  4. Plant fast-growing trees across the bog

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Review Ecology questions for Biology, with correct answers shown and coverage across communities and ecosystems; sampling methods; biodiversity and human impacts.

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