Living World: Ecosystems

Question 1

What is an ecosystem?

Answer 1

A system where biotic components (plants, animals) interact with abiotic components (climate, soil); all parts are interdependent.

Question 2

What are biotic components?

Answer 2

Living parts of an ecosystem, e.g. plants, animals, bacteria.

Question 3

What are abiotic components?

Answer 3

Non-living parts of an ecosystem, e.g. sunlight, temperature, water, soil.

Question 4

What is a biome?

Answer 4

Large-scale global ecosystem found in specific climate zones; made up of many smaller ecosystems.

Question 5

What is a producer?

Answer 5

An organism that makes its own food using sunlight (e.g. plants).

Question 6

What is a consumer?

Answer 6

An organism that eats other organisms to get energy (e.g. fox).

Question 7

What is a decomposer?

Answer 7

Organism that breaks down dead material, returning nutrients to the soil (e.g. fungi, bacteria).

Question 8

What is a food chain?

Answer 8

A linear sequence showing who eats whom in an ecosystem.

Question 9

What is a food web?

Answer 9

A complex network of interconnected food chains showing feeding relationships.

Question 10

How do food chains and food webs differ?

Answer 10

Food chains show one path of energy flow, food webs show many interlinked paths.

Question 11

What is nutrient cycling?

Answer 11

The movement and exchange of nutrients (like nitrogen and phosphorus) between living organisms and the environment.

Question 12

What are sources of nutrients in ecosystems?

Answer 12

Weathered rock, rainfall, atmosphere and decomposition.

Question 13

What happens when ecosystems change slowly?

Answer 13

The ecosystem can adapt gradually without major disruption.

Question 14

What happens when ecosystems change suddenly?

Answer 14

Disruption can occur if the change is fast or extreme, affecting interdependence.

Question 15

Example of change: disease

Answer 15

Reduces one species population, affecting predators or prey; disrupts food chains.

Question 16

Example of change: extreme weather

Answer 16

Flooding or drought can kill species or alter conditions beyond survival limits.

Question 17

Example of change: climate change

Answer 17

Alters temperature and rainfall patterns, changing species distribution and survival.

Question 18

Example of change: natural disaster

Answer 18

Events like hurricanes or wildfires destroy habitats and alter nutrient cycles.

Question 19

Example of change: new species

Answer 19

Non-native species can outcompete or prey on native species, changing balance.

Question 20

Example of change: construction

Answer 20

Habitat loss, fragmentation and pollution can reduce biodiversity.

Question 21

Example of change: agriculture

Answer 21

Clearing land, pesticide use and monocultures damage natural ecosystems.

Question 22

Example of change: deforestation

Answer 22

Removes tree cover, changes water cycle, causes soil erosion and habitat loss.

Question 23

What is a trophic cascade?

Answer 23

A change in one trophic level that causes ripple effects across the ecosystem.

Question 24

What is eutrophication?

Answer 24

Fertilisers washed into water cause algae growth, blocking light, stopping photosynthesis, reducing oxygen and killing aquatic life.

Question 25

What determines the distribution of biomes?

Answer 25

Latitude: due to global atmospheric circulation, winds, ocean currents and temperature differences between land and sea.

Question 26

Where is the tundra biome found and what are its features?

Answer 26

Found near Arctic Circle; cold, dry, with short summers; low biodiversity; permafrost; mosses and lichens dominate.

Question 27

Where is the taiga (boreal forest) biome found and what are its features?

Answer 27

Northern hemisphere, below tundra; cold winters, mild summers; coniferous forests; wolves, bears, moose.

Question 28

Where is the temperate deciduous forest biome found and what are its features?

Answer 28

Europe, North America; 4 seasons, moderate rainfall; broadleaf trees; foxes, deer, squirrels.

Question 29

Where is the temperate grassland biome found and what are its features?

Answer 29

North America (prairies), Russia (steppes); hot summers, cold winters; grasses dominate; few trees; bison and antelope.

Question 30

Where is the desert biome found and what are its features?

Answer 30

Near Tropics (e.g. Sahara); hot days, cold nights; very dry (<250mm rain/year); cacti, camels, reptiles.

Question 31

Where is the tropical rainforest biome found and what are its features?

Answer 31

Near Equator (Amazon, Congo); hot, wet all year (over 2000mm rain/year); dense forest, high biodiversity.

Question 32

Where is the savanna biome found and what are its features?

Answer 32

Between tropics (e.g. East Africa); hot with wet and dry seasons; grasses and scattered trees; zebras, lions.

Question 33

Where is the Mediterranean biome found and what are its features?

Answer 33

Southern Europe, California; hot, dry summers, mild, wet winters; shrubs, olive trees; adapted to drought.

Question 34

What are trophic levels?

Answer 34

The stages in a food chain showing energy flow; producers at the bottom, top predators at the top.

Question 35

What is biomass?

Answer 35

The total mass of living material at a given trophic level in an ecosystem.

Question 36

Why does biomass decrease at higher trophic levels?

Answer 36

Some energy is lost as heat, waste or used in movement and life processes, so less biomass is passed on.