Ecology and the Environment

Question 1

Describe how you could use a quadratic to estimate the plant biomass in a region

Answer 1

1) random coordinates generated
2) several quadrants
3) weigh/method of weighing
4) remove animals/soil
5) multiply to total area/scaling

Question 2

What is meant by the term environment?

Answer 2

the sum of the total non-biological components of the ecosystem

Question 3

What is meant by the term population?

Answer 3

Number of organisms of the same species

Question 4

What is meant by the term community?

Answer 4

all of the populations of living organisms living in an ecosystem at a particular time

Question 5

What is meant by the term habitat?

Answer 5

The place where organisms live

Question 6

What is meant by the term ecosystem?

Answer 6

a distinct, self supporting system of organisms interacting with each other and with their physical environment

Question 7

what are the biotic factors which affect organism numbers?

Answer 7

1) disease
2) competition
3) food availibility

Question 8

what are the abiotic factors which affect organism numbers?

Answer 8

1) temperature
2) humidity/rain
3) sunlight
4) pesticides

Question 9

What is meant by the term trophic level?

Answer 9

the position of an organism in the food chain

Question 10

What is meant by the term producer?

Answer 10

plants which photosynthesise to produce food

Question 11

What is meant by the term consumer?

Answer 11

animals that eat plants or other animals

Question 12

What is meant by the term decomposer?

Answer 12

organisms which decay dead material and help to recycle nutrients

Question 13

why isn’t all energy transferred from one trophic level to the other?

Answer 13

1) some energy is lost during respiration
2) some energy is lost during excretion
3) some energy is lost during egestion
4) some energy is lost during movement
5) some energy is lost during heat loss (thermoregulation)
6) not all of each organism is eaten
7) some organisms die

Question 14

Other than carbon dioxide and methane name 3 greenhouse gases

Answer 14

1) water vapour
2) CFCs
3) nitrous oxide

Question 15

What are 5 advantages of using biological control rather than pesticide?

Answer 15

1) last longer
2) no reapplication
3) specific
4) avoids bioaccumulation
5) no development or resistance

Question 16

Describe the process of eutrophication

Answer 16

1) algae bloom
2) algae block light
3) plant death so less photosynthesis
4) bacteria/decomposers
5) respiration
6) oxygen depletion
7) death of fish

Question 17

Describe the consequences of an increase in carbon dioxide for the world’s ecosystems

Answer 17

1) greenhouse effect
2) global warming
3) melting ice caps
4) climate change
5) loss of habitat
6) extinction
7) migration (spread of disease/pests)

Question 18

Suggest why animals prefer to eat plants in some habitats rather than habitats

Answer 18

1) more nutritious
2) easier to digest
3) fewer other animals (competition)
4) fewer predators

Question 19

Suggest how countries can reduce the impact of deforestation

Answer 19

1) laws to limit deforestation

2) plant more trees

Question 20

What is the process in the nitrogen cycle which goes from nitrate ions to nitrogen gas?

Answer 20

Denitrification

Question 21

What is the process in the nitrogen cycle which goes from nitrogen gas to ammonium ions?

Answer 21

Nitrogen fixation

Question 22

What is the process in the nitrogen cycle which goes from nitrite ions to nitrate ions?

Answer 22

Nitrification

Question 23

Which organisms carry out denitrification?

Answer 23

Denitrifying bacteria

Question 24

What are the effects of adding too much nitrate to soil?

Answer 24

1) leaching
2) eutrophication
3) loss of water from plant roots

Question 25

How can farmers increase the fertility of soil?

Answer 25

1) chemical fertilisers 2) manure 3) legumes

Question 26

How can you make sure your results are reliable?

Answer 26

1) repeat 2) calculate average 3) discard anomalies

Question 27

What is the water cycle powered by?

Answer 27

Energy from the sun

Question 28

What are the biological consequences of pollution of water by sewage?

Answer 28

Increases in the number of microorganisms causing depletion of oxygen

Question 29

What are the four stages of the water cycle?

Answer 29

1) precipitation (from clouds) 2) transpiration (from trees) and evaporation (from large bodies of water e.g. lakes and the sea) 3) condensation (forming clouds)

Question 30

What is the process by which carbon goes from animals and plants into the atmosphere?

Answer 30

Respiration

Question 31

What is the process by which carbon goes from the atmosphere into plants?

Answer 31

Photosynthesis

Question 32

What is the process by which carbon goes from dead matter into the atmosphere?

Answer 32

Decomposition

Question 33

What is the process by which carbon goes from fossil fuels to the atmosphere?

Answer 33

Combustion

Question 34

What do nitrogen fixing bacteria do?

Answer 34

Convert nitrogen gas into ammonia (which is then used to make proteins in plants)

Question 35

What does decomposition do in the nitrogen cycle?

Answer 35

Produces ammonia by breaking down dead protein matter

Question 36

What do nitrifying bacteria do?

Answer 36

Oxidise ammonia to nitrites and the nitrates (which can then be absorbed and assimilated by plants)

Question 37

What do denitrifying bacteria do?

Answer 37

Break down nitrates into nitrogen gas

Question 38

What are the effects of deforestation?

Answer 38

1) leaching 2) soil erosion 3) disturbance of the water cycle 4) disturbance of the balance of atmospheric oxygen and carbon dioxide

Question 39

name the type of bacteria that live in the root nodules of legumes

Answer 39

nitrogen-fixing bacteria

Question 40

describe how ammonium ions can be converted to nitrate ions in the soil

Answer 40

1) nitrifying bacteria | 2) nitrite ions to nitrate ions

Question 41

Describe how the process of nitrification affects the availability of nitrates to plants

Answer 41

1) Nitrifying bacteria | 2) ammonia to nitrites and then nitrates

Question 42

Suggest why farmers grow legume crops and then plough them into the soil before growing their cereal crops

Answer 42

1) root nodules 2) nitrogen fixing bacteria 3) nitrogen gas to nitrates 4) amino acids/proteins 5) growth/higher yield 6) decomposition 7) decomposing bacteria/fungi 8) mineral ions

Question 43

explain how the nitrogen in a nitrate ion in the soil can become the nitrogen protein in an animal

Answer 43

1) absorption by roots/root hair cell 2) active transport 3) make amino acids 4) assimilation 5) plant is eaten/ingested by animal 6) digestion 7) protease

Question 44

suggest advantages of using animal waste as a fertiliser rather than using a chemical fertiliser

Answer 44

1) cheaper 2) less eutrophication/leaching 3) improves soil structure (stops erosion)