Ecosystems and Material Cycles

Question 1

what re the 4 different levels organisms are split into?

Answer 1

• individual
• population
• community
• ecosystems

Question 2

what is an individual organism?

Answer 2

a single organism

Question 3

what is a population organism?

Answer 3

all the organisms of one species

Question 4

what is a community organism?

Answer 4

different species living in a habitat

Question 5

what is a ecosystem organism?

Answer 5

community of organisms along with non living conditions

Question 6

what are the abiotic factors affecting communities?

Answer 6

• temperature
• amount of water
• light intensity
• levels of pollution

Question 7

what re the biotic factors effecting communities?

Answer 7

• competition- i.e. for food and resources

- predation- eat each other do decreasing numbers

Question 8

why is it important that communities are interdependent?

Answer 8

• rely on each others populations for food

- i.e. bees and flowers

Question 9

what is mutualism?

Answer 9

the relationship between two organisms

i.e bees and flowering plants

Question 10

what is parasites?

Answer 10

take what is needed to survive but the host doesn’t benefit.
i.e. flees

Question 11

how can quadrants and belt transects be used to investigate the relationship between organisms and their environment?

Answer 11

1. mark out line of area to study
2. collect data log line using quadrates, regular intervals
3. esimate percentage cover
4. repeat to find mean number of organisms
5. graph data to see correlation

Question 12

what is eutrophication?

Answer 12

• excess amount of nutrients in water

- impact of human on biodiversity

Question 13

how is eutrophication causes?

Answer 13

• nitrates put on fields as fertilisers

- when it rains, nitrates get into ground water and go to rivers

Question 14

what are the negatives of eutrophication?

Answer 14

• nitrates cause algae to grow backing sunlight on rivers

- fish die. no oxygen

Question 15

how catfish farms reduce biodiversity?

Answer 15

• food added to nets creating waste in water, leading to eutrophication
• predators become attracted to nets, getting trapped killing them. i.e. sea lions
• can become breading ground for parasites

Question 16

how can reforestation increase biodiversity in deforested areas?

Answer 16

-replanting a variety will increase biodiversity and attract new animals that can reproduce

Question 17

how can conservation schemes increase biodiversity?

Answer 17

• prevents species from dying out
• protect natural habitats
• breeding programs

Question 18

what are the 6 main benefits for maintaining a high diversity?

Answer 18

• human food supply
• minimal damage to food chains
• future medicines
• cultural aspects
• ecotourism
• providing new jobs

Question 19

what materials are constantly being passed through the abiotic and biotic components in an ecosystem?

Answer 19

• oxygen
• carbon
• proteins
• waste produced, like dead things decompose

Question 20

how does the carbon cycle work?

Answer 20

• powered by photosynthesis
• animals eat plants which pass it on
• animals respire releasing back into the air
• when plants and animals die, they decompose releasing CO2
• fossil fuels release CO2

Question 21

how does the water cycle work?

Answer 21

• sun evaporates water from land, sea and plants
• water cools, condenses and falls as precipitation
• process starts again

Question 22

how can desalination be used to produce portable water?

Answer 22

• removes salts from salt water
• thermal distillation
• heat so water vaporises and salt stays at bottom
• condense evaporated water

Question 23

what is the nitrogen cycle?

Answer 23

• 78% nitrogen
• plants absorb mineral ions and use nitrogen to make proteins
• decomposers break down dead plants containing nitrogen

Question 24

what are the 4 main bacterias used in the nitrogen cycle?

Answer 24

• decomposers
• nitrifying bacteria
• nitrogen-fixing bacteria
• denitrifying bacteria

Question 25

how do farmers increase the amount of nitrates in the soil?

Answer 25

• crop rotation sometimes planting peas or beans to help replenish soil with nitrogen
• fertilisers