Chapter 35 - Human Influence on then Environment Flashcards
Name 5 ways in which modern technology has been utilised to increase food production
- Mechanical methods (Machinery)
- Use of fertilisers increases crop yield
- Pesticides prevent destruction of crops
- Genetic engineering produce organisms resilient to disease
- Development of chemistry and processing techniques processes once-useless byproducts
Define deforestation
The removal of large numbers of trees and forests
Suggest causes for deforestation
- People wants to use the land for agriculture and urban use
- Uncontrolled fires
- Firewood
- Construction material
- Furniture and wood carvings
- Overgrazing
- Hunters burn trees to chase out animals
Describe the effects of deforestation
- More soil erosion
- Flooding
- Leaching causes infertile soil
- Less photosynthesis results in global warming and less rain
- Less rain (less transpiration)
- Destruction of habitats
- Extinction of species
- Extinct species means the loss of a medicine source
- Disruption of food chains and webs
- More pollution
- Less tourism (less income)
Describe a fertiliser
Concentrated source of plant nutrients in chemical or organic form. Fertilisers increase plant growth and crop yield. Fertilisers are also used where plants show nutrient deficiency
Describe the effects of the over use of fertilisers on the environment
- Leaching
- Algae bloom
- Algae block out light
- Eutrophication
- Aquatic plants die
- Decomposers use up oxygen
- Other species die or migrate
Name 4 alternatives to using industrially produced fertilisers
- Nitrogen fixing crops (Legume plants)
- Crop rotation
- Organic fertilisers
- Green manure
Describe the responsible use of fertilisers
Apply the correct amount, never apply when rain is in forecast, never spray near water sources and never spray on open fields
Name 5 advantages of crop rotation
- Improve yield
- Improve soil structure
- Less diseases
- Less pesticides required
- No leaching
Suggest one reason for which a farmer would replace industrial fertilisers with organic fertilisers
Less expensive and uses already availible materials
Define a pesticide
A chemical compound used to kill pests
Describe the negative effects of pesticides on the environment
- Pesticides are non-biodegradable
- Bioaccumilation, meaning pesticides become part of living organisms
- Biomagnification, which means pesticides become more concentrated along the food chain
- High concentrations of pesticides cause serious harm to animals and humans
- Wide-spectrum pesticides kill many organisms and not only pests
- Usefull organisms like pollinators can be killed
- Too much pesticides can cause pests to develop resistance to pesticides
Name two ways in which damage caused to the environment by pesticides can be reduced
- Fewer pesticides
- More specific pesticides
Describe biological control
The use of one species to control another. Control pests by using their natural enemies to disrupt their breeding cycle and reduce the pest’s numbers. The control organism must become part of the food chain and not a pest itself. The enemy must be very specific
Name three advantages of biological control
- Natural enemy only attacks pest
- Pest cannot become resistant
- Alternative to pesticides
Name two disadvantages of biological control
- Cost of research is expensive
- Control organism may become a pest
Discuss the effects of irrigation on the environment
- Crops can be watered in dry seasons
- Soil erosion
- Soil loses fertility
- Water logging
- Salinisation (leaving behind of poisonous salts)
- Expensive
- Wastage of water
Name 4 effects of acid rain on humans and human structures
- Corrodes limestone
- Corrodes metals
- Risk of consuming shellfish or fish contaminated with mercury
- Economic impact on tourism and fishermen
Name three effects of acid rain on water
- Poisonous aluminium and mercury end up in water sources and poison aquatic organisms
- Kills plankton, frogs, snails and fish
- Damages groundwater and drinking water
Name 5 effects of acid rain on plants
- Dissovles nutrients which causes leaves to turn brown and fall off
- Aluminium damages fine root hairs
- Reduces the productivity of farmland
- Destruction of photosynthetic tissues
- Attacks the waxy cuticle on plants, meaning more water loss
Suggest 5 ways in which acid rain can be reduced
- Emission gases can pass through scrubbers
- Catalytic converters
- Limiting of fossil fuels
- Coal can be crushed and washed
- Oil can be treated
Describe the effects of oil on the ocean
- Birds cannot fly
- Birds lose insulation and die of hypothermia
- Birds become poisoned
- Fish are poisoned and gills covered in oil
- Oil destroys food webs and chains
- Blocks out sunlight from aquatic plants
- Visual impact and loss of tourism
- Less photosynthesis for seaweed, meaning less oxygen
- Kills shellfish
- Fishermen lose income
Describe the effects of oil on fresh water
- Pollutes drinking water
- Chemicals kill bacteria which cause sewage works to be less effective
- Lack of water for irrigation
Suggest 8 ways in which oil pollution can be reduced
- Spray detergents which break up oil
- Oil can be burned
- Barriers to contain oil
- Oil can be sucked up by feathers
- Micro-organisms can digest oil
- Strict control in handling of oil
- Severe fines
- Regular inspection and maintainance of tankers
Define sewage
Polluted water from kitchens and bathrooms which contain faeces, urine, bacteria and parasites
Describe the environmental problems caused by sewage
- Disease
- Non-parasitic diseases
- Parasitic diseases
- Transmitted to humans if sewage is not treated or consumed
- Aerobic bacteria (decomposers) reduce the amount of oxygen in the water
- Other organisms die or migrate, causing less biodiversity
- Nitrates and phosphates are released into the water
- Eutrophication
- Chemical detergents cause biomagnification and bioaccumilation
- Methane
- Hydrogen sulfide (unpleasant smell)
Describe the environmental problems caused by inorganic waste
- Bioaccumilation
- Serious health problems when consuming contaminated fish (cancer and birth defects)
Name four effects of radioactive waste on humans
- Cancer
- Radiation sickness
- Birth defects
- Damage to the nervous system
Name the effects of plastics on the environment
- Mammals, marine birds and marine mammals mistake plastics for food and choke and die
- Marine organisms get strangled
- Clog waterways and spoil the landscape
- Get wrapped around branches and fences and spoil the landscape
- Production causes polluting gases
- Plastic bottles and containers float in oceans
