human influences on ecosystems

Question 1

fertilizer

Answer 1

substance that contains important nutrients for plant growth, such as magnesium and nitrates

Question 2

insecticides

Answer 2

substances that kill insectsand, in doing so, protect the crop plants from damage

Question 3

herbicides

Answer 3

substances that kill plants by disrupting their growth in some way

Question 4

monoculture

Answer 4

growing only one variety of crop in an area at a given time

Question 5

advantages of intensive farming

Answer 5

• Simplicity
• Higher yields
• Reduced costs
• Larger land and machinery

Question 6

disadvantages of intensive farming

Answer 6

• Negative impacts on the environment, such as:
  
  • Land clearance
  • Deforestation
  • Reduced biodiversity
  • Soil damage
  • Water pollution
  • Air pollution

Question 7

biodiversity

Answer 7

diversity of living organisms in an ecosystem

Question 8

habitat

Answer 8

place where an organism lives

Question 9

Human activities that lead to the destruction of habitats:

Answer 9

• using more land for food crops, livestock production and housing
• the extraction of natural resources
• freshwater and marine pollution

Question 10

The extraction of crude oil and natural gas destroys habitats because:

Answer 10

• pollution is created by fuels when they are burned
• the search for oil or gas damages natural habitats
• drilling and mining operations need wells, roads, pipelines and other facilities

Question 11

Sources of water pollution:

Answer 11

• oil spills
• untreated sewage
• careless disposal of rubbish
• mining waste
• nitrates entering rivers from fertiliser use
• herbicides and pesticides
• heavy metal runoff (this can carry toxic metals such as mercury that pose a danger to water life and human health

Question 12

Deforestation may lead to:

Answer 12

• reduced biodiversity
• flooding
• loss of soil
• extinction of species
• an increase in carbon dioxide in the atmosphere

Question 13

Pollution meaning

Answer 13

the release of any substance that has an undesired, unexpected, harmful or toxic effect on the environment

Question 14

Source of pollution

Answer 14

how and where the pollutant enters the environment

Question 15

Effect of pollution

Answer 15

the harm that the pollutant does when it is in the environment

Question 16

Source of untreated sewage

Answer 16

human and animal waste released without passing through sewage treatment plants

Question 17

Effect of untreated sewage

Answer 17

may carry harmful pathogens that cause disease; uses up oxygen when it rots; hormones affect reproduction of some organisms

Question 18

Source of fertilizers

Answer 18

runoff from farmland

Question 19

Effect of fertilizers

Answer 19

algal blooms and eutrophication

Question 20

Sustainable resource

Answer 20

something that is produced as rapidly as it is removed from the environment, so that it does not run out

Question 21

Non-sustainable resource

Answer 21

resources that are used up faster than they are being formed

Question 22

Factors endangering species:

Answer 22

• destruction of habitat
• pollution
• climate change
• hunting
• introduced species
• overharvesting.

Question 23

Endangered species can be conserved by taking steps such as:

Answer 23

• monitoring and protecting species and habitats
• education
• seed banks
• captive breeding programmes

Question 24

Reproduction in captivity:

Answer 24

• Artificial insemination
• In-vitro fertilisation