Human Effects on the environment

Question 1

Describe how CITES may help to conserve a species. (2 marks) 3 points

Answer 1

1. International trade has been banned/restricted
2. Makes trade illegal/lowers demand/unprofitable
3. Therefore, reduction in poaching/hunting

Question 2

Give 2 reasons why orangutans should be conserved. (2 marks) 5 points

Answer 2

1. To prevent extinction
2. Moral/ethical/stewardship
3. Educational/scientific medical research
4. Aesthetic/recreational reasons
5. Qualified economic benefit e.g. income from tourism

Question 3

Give 2 economic reasons why wildlife conservation is important. (2 marks) 4 points

Answer 3

1. Medicines
2. Oils
3. Wood
4. Ecotourism

Question 4

Explain how other organisms may benefit from the conservation of flagship species. (2 marks) ???????

Answer 4

1. De?????????
2. Habitat protected
   3.

Question 5

Explain how the listing of elephants under CITES has helped to reduce elephant hunting. (2 marks)

Answer 5

1. International trade has been banned/restricted.
2. Market has declined/less demand.
3. Less profit for ivory
4. Reduction in poaching due to lower sales

Question 6

Explain how net size restrictions protect fish stock. (1 mark)

Answer 6

1. Large mesh so limits capture of small/immature fish.
2. Small nets limit size of catch so less effect on population.
3. Smaller nets gives less by-catch.

Question 7

Explain how close season regulations protect fish stock. (1 mark)

Answer 7

1. Close season-allows reproduction.

Question 8

F4????Explain the effect of fishing effort on the size of catch. (3 marks)

Answer 8

2. 3.

Question 9

How does a quota prevent the fish stock declining? (1 mark)

Answer 9

1. Limiting no. of fish caught so greater chance of chance of individuals surviving to breed.

Question 10

Give 1 reason why a quota is not always effective in preserving fish stocks. (1 mark) 5 points

Answer 10

1. Fish caught above quota have to be returned-these are unlikely to survive.
2. Quotas exceeded illegally.
3. Quotas too high
4. Fish eaten by predators
5. Small fish may be caught

Question 11

Explain what’s meant by the maximum sustainable yield in fisheries. (2 marks) ????

Answer 11

1. The amount of fish that can be caught and allow the population to remain constant and high
2. Where difference between birth and death rates is maximum.

Question 12

Explain the meaning of global warming. (2 marks)

Answer 12

1. Gradual increase in temp

2. Of earth’s atmosphere and oceans

Question 13

Describe and explain how the effects on plant species could affect animal species. (3 marks) 4 points

Answer 13

1. Reduction of herbivore/primary consumer
2. This would result in the reduction of predator/secondary consumer
3. Change in the distribution of plants could result in a change of distribution of herbivores.
4. Loss of shelter provides more food for predators so they would increase in size/no.

Question 14

Describe and explain how global warming can affect plant species. (4 marks)

Answer 14

1. Loss of existing species/extinction]
2. Changes in distribution of plants
3. Changes in no.s/growth of plants/species
4. as there will be changes in rainfall patterns
5. Change in growing seasons
6. Temp may become too hot for some species
7. Increased CO2 results in more photosynthesis/GPP/NPP
8. Fall in ph in rivers/oceans

Question 15

Explain why an increase in CO2 conc can cause the temp of the atmosphere to change. (1 mark)

Answer 15

1. Absorption of infrared/long-wave

Question 16

Describe the methods that may be used to reduce atmospheric conc of greenhouse gases. (4 marks)
?????? 15 points

Answer 16

1. CO2
   a) Energy conservation/change in transport system to reduce fossil fuel use
   b) Use of wind/hydroelectricity etc
2. Methane
   a) Reduced use of landfill for more recycling/less waste
   b) Changed livestock diet to reduce methane release
   c) Coal mine and petroleum/natural gas recollection
3. CFCs
   a) Use HFCs
   b) Use stick deodrants/pump action sprays instead
   c) Incineration should be used
4. NOx
   a) Energy conservation
   b) Use renewbele energy source e.g geothermal, hydroelectric, wind, tidal
   c) Catalytic converter
   d) Urea sprays
   e) Low temp combustion

Question 17

Explain why an increase in teh temp of the atmoshpere can cause CO2 conc to increase. (1 mark) 6 points

Answer 17

1. Increased rate of process involving CO2, e.g. a)respiration,
   b) decompositon,
   c) forest fires,
   d) evolving of CO2 from oceans,
   e) photosynthesis,
   f) coming out of solution

Question 18

Outline 2 reasons why global climate change may cause sea level to rise. (2 marks)

Answer 18

1. Thermal expansion

2. Melting of ice caps/glaciers

Question 19

Suggest how coastal areas that are high enough to avoid flooding may still be threatened by sea level rise. (1 mark)

Answer 19

1. Increased coastal erosion

2. Saltwater incursion

Question 20

Suggest 1 source of evidence apart from growth ring studies that can be used to estimate changes in mean environmental temp in Nepal over the last 400 years (1 mark) 3 points

Answer 20

1. Estimates of CO2 levels in air
2. Pollen from peat
3. Temp records

Question 21

Suggest why these bacteria need to have special adaptations to live in the stomach of a cow. (3 marks) 7 points

Answer 21

1. Low pH in the stomach(HCL)
2. Acid destroys bacteria
3. No/low oxygen
4. therefore would need to use anaerobic respiration
5. Need to be resistant to stomach enzymes (protease)
6. Bacterial cell needs to be resistant to digestion
7. Needs to adapt to cows temp