Human influences on the ecosystem

Question 1

How has modern technology increased food production?

Answer 1

Agriculture machinery- improved efficiency
Chemical fertilisers improve yields
Insecticides and herbicides- reduced competition
Selective Breeding- Reliably made to produce high yields

Question 2

What are the negative impacts of monocultures?

Answer 2

1. Biodiversity is low
2. Increase in pest populations
3. Leads to insecticides being sprayed which kills harmless insects, pollution, pests becoming resistant

Question 3

What is the negative impacts of intensive livestock farming?

Answer 3

1. Reduction in biodiversity
2. Overgrazing leads to soil erosion
3. Large amounts of cattle produce a lot of methane- greenhouse gas

Question 4

What are livestock usually fed?

Answer 4

High energy foods and antibiotics as a presentative measure against disease

Question 5

How can famine occur?

Answer 5

When people do not receive enough food

Question 6

What can cause famines?

Answer 6

Natural disasters- drought and flooding
Increasing population
Poverty
Unequal food distribution

Question 7

Describe the problem of global food supply

Answer 7

More land is needed to grow crops/animals-deforestation-increasing amount of greenhouse gas- global warming- tropical storms and drought-flooding- destruction of habitable food

Question 8

What are the reasons for habitat destruction?

Answer 8

– increased area for food crop growth, livestock
production and housing
– extraction of natural resources
– marine pollution

Question 9

What is deforestation?

Answer 9

The clearing of trees

Question 10

What can be caused by altering food webs and food

chains?

Answer 10

Humans suffer a negative impact

Question 11

What are the undesired effect of deforestation?

Answer 11

Extinction of species
Loss of soil
Flooding
Increase of carbon dioxide in atmosphere

Question 12

Explain how soil erosion can be caused by deforestation

Answer 12

Trees roots stabilise the soil-preventing it from being eroded from rain
Trees take nutrients from the soil and if there weren’t any trees these would wash into lakes

Question 13

State sources of pollution

Answer 13

Industry, manufacturing processes, discarded rubbish, nuclear fall out and untreated sewage

Question 14

Give two examples of greenhouse gases?

Answer 14

Carbon dioxide and methane

Question 15

What do greenhouse gases do?

Answer 15

Contribute to the enhanced greenhouse effect

Question 16

What are the effects of non-biodegradable plastics on the marine?

Answer 16

Animals try to eat plastic leading to injuries and death
Plastic breaks down it releases toxin
Once it breaks down it releases toxins and enters the food chain

Question 17

What are the effects of non-biodegradable plastics on land?

Answer 17

Burying in landfills

It releases toxins and so the surrounding soil is no good for growing crops or grazing animals

Question 18

What is the effect of female contraceptive hormones?

Answer 18

Causes feminisation in males- affects food chains as less reproduce- males sperm count is reduced

Question 19

What creates sulphur dioxide?

Answer 19

Combustion of fuels containing sulphur impurities

Question 20

What are possible solutions to reduce acid rain?

Answer 20

Changing power stations to renewable sources
Using scrubbers to remove sulphur dioxide from factory chimneys
Catalytic converters in car exhausts

Question 21

What are greenhouse gases?

Answer 21

Absorbs infrared radiation from the Sun so it remains trapped in the Earth’s atmosphere

Question 22

What happens to an excess of greenhouse gases?

Answer 22

The Earth’s average temperature rises

Question 23

What are the most important greenhouse gases?

Answer 23

Water vapour
Carbon dioxide
Methane
Nitrous oxides
CFC's

Question 24

What are consequences of global warming?

Answer 24

ocean temperatures increase
extreme weather 
changes in loss of habitat
decrease in biodiversity
increase in migration

Question 25

Define sustainable resource

Answer 25

It is produced as rapidly as it is removed from the

environment so that it does not run out

Question 26

Define sustainable development

Answer 26

development providing for the needs of an
increasing human population without harming
the environment

Question 27

What must be taken into consideration when developing a way in which we use resources to manage them sustainably?

Answer 27

1. The need for local people to be able to utilise the resources they have
2. The need for balancing hte needs of humans for resources with the needs of animals and plants that live in the area
3. The need to balance what current populations need with what future populations might need

Question 28

What do we need forests for?

Answer 28

To produce paper

Provide wood for timber

Question 29

What ensures the sustainment of forests?

Answer 29

Monitor logging companies that track wood produced

Education

Question 30

How can you sustain fish stocks?

Answer 30

Controlling the number of fish caught each year
Controlling the size of the fish caught
Controlling the time of the year that certain fish can be caught
Restocking
Educating fishermen

Question 31

What are endangered species at risk of?

Answer 31

Extinction

Question 32

Why may a population of species fall below critical level?

Answer 32

Hunting
Climate change
Pollution 
Loss of habitat
Introduction of non-native species

Question 33

How can endangered species be helped?

Answer 33

Education programmes
Captive breeding programmes
Monitoring and legal protection of the species
Seed banks as a conservation for plants

Question 34

What are the reasons for conservational programmes?

Answer 34

Reducing extinction rates of both plant and animal species
Keeping damage to food chains minimal
Protecting vulnerable ecosystems
Protecting our future food supply and maintaining nutrient cycles