human influences on environment and use of biological resources rev

Question 1

consequences of SO2

Answer 1

Acid rain - damages plants, increases soil pH, wears away bridges
Respiratory problems

Question 2

consequences of CO

Answer 2

binds to haemoglobin in preference to O2 - suffocation and death

Question 3

name the greenhouse gases

Answer 3

water vapour, carbon dioxide, nitrous oxide, methane and CFCs

Question 4

how does human activity lead to more greenhouse gases

Answer 4

burning fossil fuels - more CO2
cattle production - more methane
rice paddy fields - more methane

Question 5

describe greenhouse gas effect

Answer 5

• the Sun emits rays that enter the Earth’s atmosphere
• heat bounces back from the Earth’s surface as infrared radiation
• some heat is reflected back out into space
• some heat is absorbed by greenhouse gases and is trapped within the Earth’s atmosphere, excess greenhouse gases mean earth’s temp increases

Question 6

impacts of global warming

Answer 6

• Ocean temperatures increasing, causing melting of polar ice caps / rising sea levels / flooding / coral bleaching
• Increasing temperatures causing extreme weather like super storms, flooding, droughts
• Changes in or loss of habitats due to these extreme weather events
• Decreases in biodiversity as food chains are disrupted and extinction rates increase
• Increases in migration of species to new places, including increased spread of pests and disease

Question 7

what happens when fertilisers leach into water

Answer 7

eutrophication

Question 8

effects of sewage pollution

Answer 8

sewage - aerobic bacteria feed on it - reduce oxygen levels in water - other organisms die

Question 9

impacts of deforestation

Answer 9

• leaching - soil minerals washed away by rain, not taken up
• soil erosion
• disturbance of the water cycle - reduces transpiration
• disturbance of the balance in atmospheric oxygen and CO2 - less photosynthesis, more CO2

Question 10

how do glasshouses increase crop yield

Answer 10

• Artificial heating (enzymes controlling photosynthesis can work faster at slightly higher temperatures - only used in temperate countries such as the UK)
• Artificial lighting (plants can photosynthesise for longer)
• Increasing carbon dioxide content of the air inside (plants can photosynthesise quicker)
• Regular watering (irrigation)

Question 11

how do polythene tunnels increase crop yield

Answer 11

• More commonly called polytunnels, these are large plastic tunnels that cover crops
• They can protect crops grown outside from the effects of the weather, including excessive wind, rain and extreme temperatures
• They also increase the temperature slightly inside the tunnel
• They can prevent the entry of pests that can damage plants or diseases that can kill plants

Question 12

what are the limiting factors of photosynthesis

Answer 12

temp, light intensity, CO2

Question 13

what do plants need nitrogen for

Answer 13

• Absorbed in the form of nitrates
• Needed to make amino acids which are the building blocks of proteins

Question 14

two types of fertiliser and what fertilisers are for

Answer 14

organic and chemical, used to provide more mineral ions, so plants grow bigger and faster and yield increases

Question 15

what do plants need phosphorous for

Answer 15

• Absorbed in the form of phosphates
• Needed to make DNA and cell membranes

Question 16

what do plants need potassium for

Answer 16

• Absorbed in the form of various compounds of potassium
• Allows enzyme reactions to take place to produce ATP in respiration as well as being needed for the enzymes involved in photosynthesis

Question 17

two methods of pest control

Answer 17

Pesticides (chemical that kills)
Biological control (intro of a predator)

Question 18

advantages of pesticides

Answer 18

• easily accessible
• relatively cheap
• works immediately
• kills entire population of pests

Question 19

disadvantages of pesticides

Answer 19

• target organism can develop resistance
• can kill other organisms
• bioaccumulation
• need to be repeatedly applied

Question 20

what is bioaccumulation

Answer 20

When pesticides don’t break down in body and accumulate in body of predator top of food chain

Question 21

advantages of biological control

Answer 21

• no pollution (natural)
• no resistance
• can target specific species
• long lasting
• no need to reapply

Question 22

disadvantages of biological control

Answer 22

• may eat other organisms, not pests
• takes longer to be effective
• cannot kill entire population
• may move out of area/ not adapt to new environment
• may become a pest itself

Question 23

role of yeast in beer making

Answer 23

Anaerobically respires (fermentation), using sugar to make ethanol and CO2

Question 24

what is the role of bacteria in yoghurt making

Answer 24

Digests milk proteins and converts lactose (sugar) into lactic acid

Question 25

what bacteria are used in yoghurt making

Answer 25

Lactobacillus bulgaricus Streptococcus thermophilus

Question 26

Parts of an industrial fermenters

Answer 26

Steam inlet/outlet pipes Inlet pipe/ exhaust outlet pipe Temp and pH probes Cold water inlet and water jacket Air inlet pipe and filter Motor and stirring paddles Stainless steel surrounding Harvesting outlet pipe

Question 27

how do industrial fermenters have aseptic conditions

Answer 27

cleaned with steam