l5 human impact and food production

• what gases form acid rain?

  sulfur dioxide and nitrogen oxide
• describe sulphur dioxide?

  -produced by combustion of fossil fuels

  -dissolves in water to form sulphuric acid
• what are the greenhouse gases?

  carbon dioxide, methane, water vapor, nitrous oxide , CFC's
• describe water vapour and carbon dioxide?

  -produced by the combustion of fossil fuels
• describe methane?

  -produced by decomposition

  -released in rice paddy fields
• how is carbon monoxide produced?

  -incomplete combustion
• what is the affect of carbon monoxide?

  reduces oxygen in the blood
• how is global warming caused?

  -greenhouse gases increase reflection of radiation resulting in enhanced greenhouse affect
• what are the affects of enhanced greenhouse affect?

  -global warming

  -ice cap melting

  -sea levels rise

  -habitat loss

  -climate change

  -droughts

  -extinctions

  -change in distribution of organisms

  -ocean acidification

  -coral reef bleaching
• what are 2 water polluters?

  -pesticide and herbicides-fertilisers
• what are the affects of pesticides and herbicides?

  -bioaccumulation and biomagnification
• what are the effects of fertilisers?

  -Eutrophication
• what s the definition of bioaccumulation?

  -The increase in concentration of a chemical substance in an organism
• what is the definition of biomagnification?

  the increase in concentration of a chemical substance at each trophic level
• describe the process of eutrophication?

  -Fertilisers leach into river

  -algae grows using the fertiliser causing an algal bloom

  -algal bloom results in less light reaching aquatic plants

  -plants cannot photosynthesis and die

  -decomposers decompose dead algae and plants by decomposition / respiration reducing oxygen levels in the water

  -water becomes anoxic and the fish die
• what are the effects of deforestation?

  -habitat loss

  -decrease in biodiversity

  -leaching

  -disruption of water cycle

  -changes patterns in rainfall

  -droughts

  -increase in CO2,decrease in O2 due to photosynthesis
• what are pests?


  organisms that reduce the yield of crops or animals
• what are pesticides?


  chemicals used to control pests
• what are the different types of pesticides? herbicides-kill plantsinsecticides - insects

  fungicide's -kill fungi
• what are the advantages to pesticides?

  -quick to kill
• what are the disadvantages to pesticides?

  -needs reapplication

  -insects can become more resistant to pesticides

  -can enter food chains and cause bioaccumulation

  -kills non specific insects

  -can affect human health
• leaching of pesticides does not cause ----------?

  eutrophication
• what is the definition of biological control?

  -use of an organism to reduce the number of pests to a non significant level (not 0)
• what are the advantages of biological control?

  -no need to reapply

  -no resistance

  -no bioaccumulation

  -specific
• what are the disadvantages to biological control?

  -may eat other organisms instead of pests

  -the organism can become a pest
• why are fish farms used?

  -to ensure high yield

  -mitigate overfishing
• how do fish farms maximise production?

  -nets to prevent predation

  -separates different species

  -separates fish of different sizes to prevent predation

  -feed food frequently but in small quantity's to prevent accumulation

  -use antibiotics to reduce disease

  -remove faeces / dead fish / algae

  -aerate water / use pumps to maintain oxygen levels

  -selective breeding of fish with desirable characteristics
• what is selective breeding?

  -process by which a human selects and breed individuals with desirable characteristics
• what are the steps to selective breeding?

  -select individuals with ------------------- (characteristics)

  -breed the individuals together to produce offspring

  -select and breed the offspring with desirable characteristics

  -repeat the process over many generations
• what is a product of yeast?

  bread dough
• describe yeast?

  -carry's out anaerobic respiration

  -glucose--->ethanol +carbon dioxide

  -carbon dioxide causes dough to rise

  -build up of ethanol causes yeast to die
• what is a product of bacteria (lactobacillus)

  -yogurt
• how is yogurt made?

  -lactobacillus converts lactose into lactic acid to make yogurt
• what does the oil do in fermentation of yeast?

  -prevents oxygen from entering the solution preventing aerobic respiration
• how do you investigate the affect of temperature on the anaerobic respiration of yeast?

  -place the solution in a water bath
• how do you measure the rate of anaerobic respiration?

  -measure the number of bubbles

  -or measure volume of CO2
• what is the function of the temperature monitor?

  -helps monitor temperature to maintain optimum temperature
• what is the function of a cooling jacket?

  -lets cooling water in preventing overheating and enzymes denaturing
• what is the function of the air inlet?

  -allow oxygen in for aerobic respiration
• what is the function of the air filter?

  -to prevent bacteria contamination