B18 - Biodiversity and Ecosystems Flashcards

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1
Q

What is biodiversity

A

The variety of all the different species on earth or in an ecosystem

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2
Q

Advantages of a high biodiversity

A
  • Makes an ecosystem stable + more resilient to environmental changes
  • Ecosystem is less dependant on only one species
  • This could be for food or shelter
  • If the population of a species falls, it won’t affect the whole ecosystem
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3
Q

Reasons for deforestation

A
  • To grow rice fields or for cattle grazing
  • The grow crops to be used to make biofuels
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4
Q

Ways deforestation impacts the environment

A
  • Burning trees releas CO2
  • Decomposing trees release CO2
  • Lack of trees reduces absorbtion of CO2
  • Loss of biodiversity
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5
Q

What has the population increase lead to?

A
  • Increased use of Earth’s resources
  • More waste products
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6
Q

How is water pollution caused and its effects

A
  • Sewage contain huamn excretemnt is released into rivers or streams
  • Fertilisers from farms
  • Toxic chemicals from factories
  • This kills aquatic organisms - reduing biodiversity
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7
Q

How is air pollution caused and what are its effects

A
  • Burning fossils fuels can cause acid rain
  • Also releases large particulates which are pollutants
  • This kills animals and plants and reduces biodiversity
  • Also causes global dimming and health issues
  • Carbon dioxide - global warming, changing migration, extreme weather, loss of habitat
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8
Q

How is land pollution caused and what are its effects

A
  • Waste dumped in landfills - reduces habitats
  • Toxic chemicals e.g. heavy metals pollute soil killing organisms
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9
Q

Steps in eutrophication

A
  • Nitrates get in water
  • Leads to algal bloom
  • PLants beneath die from lack of light
  • Algae then die
  • Bacteria decompose algae and use up oxygen
  • Fish and organisms die
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10
Q

What is bioaccumulation

A
  • Chemicals get into the food chain
  • Chemical remain in animals tissues
  • Over time, chemical levels will increase as they take in more
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11
Q

What is biomagnification

A
  • The concentration of chemicals increases in tissues of organisms as you move along a food chain
  • Affects top predators the most
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12
Q

How do humans reduce land available for organisms

A
  • Infrastructure
  • Farming
  • Quarries
  • Landfill
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13
Q

What is peat and what are its advantages

A
  • Dead plant material that hasn’t decayed due to acidic conditions in bogs
  • They trap CO2
  • Provide a habitat for lots of unique organisms
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14
Q

What is peat used for and disadvantages of this

A
  • Used for cheap compost
  • Burned to produce electricity or for heat
  • This reduces biodiversity
  • Peat decays once extracted releases CO2
  • Burning peat also releases CO2
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15
Q

Biological consequences of global warming

A
  • Loss of habitats
  • Bleaching of sea corals
  • Animals extend range to originally cooler areas
  • Migration patterns changing
  • Crops can’t be grown in too hot conditions
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16
Q

How can biodiversity be maintained

A
  • Breeding programs for endangered species, avoiding inbreeding
  • Protection and regenration of rare habitats (coral reefs, mangroves)
  • Growing hedgerows or field margins
  • Reducing deforestation
  • Reducing CO2 emissions
  • Recycling resources - less in landfills
17
Q

What are apex predators

A
  • Carnivores with no predators
  • This means they are at the top of the food chain or at the highest trophic level
18
Q

What is biomass and how do you calcuate it

A
  • The dry mass of material in a living organism
  • Therefore, the organism has to be killed and dried
  • Wet biomass is inaccurate as moisture of organisms varies
19
Q

What is the 1% and 10% rule

A
  • 1% of light hitting the ground is absorbed by plants fro photosynthesis
  • 10% of the original biomass is passed onto the next trophic level
20
Q

How does the 10% rule affect the number of organisms at each trophic level

A
  • Food chains aren’t lonnger than 5 levels as there isn’t enough energy transferred
  • As you go up, the number of individuals decreases
21
Q

Why isn’t all biomass transfered between each trophic level

A
  • Glucose (biomass) is used in respiration to make energy
  • Not all parts of an organism are injested
  • Not all injested material is absorbed, some just gets egested
  • Some is used in maintaining body temp.
  • Some is lost as waste products from reactions e.g. urea
22
Q

how to calculate the efficiency of biomass transfer

A

efficiency = gain in biomass/total biomass intake

23
Q

Biological factors which are threatening food security (6)

A
  • Increasing birth rate
  • Changing diets in developed countries
  • New pests and pathogens
  • Environmental change due to climate change
  • Cost of agricultural resources
  • Conflicts
24
Q

Advantages and diasdvantages of factory farming

A

Advantages - more efficient, gives animals optimum nutrients needed, eggs can be easily harvested

Disadvantages - spread of pathogens, antibiotic reistant bacteria, animals get stressed, ethical issues

25
Q

What is intensive (factory) farming

A
  • Animals have limited movement
  • The temperature conditions are kept ideal
  • They are fed a high protein diet
  • This wastes less biomass and is more efficient
26
Q

Why are fish stocks declining and what are the problems with this

A
  • Trawlers can stay at sea for weeks
  • They catch many tons of fish at a time
  • This leads to there not being enough mature fish to breed
27
Q

Strategies for fish stock conservation

A
  • Strict quotas of the number of fish that can be caught - however this can lead to dead fish just being thrown back into the sea
  • Net size must have large enough holes so smaller fish can grow and reproduce
28
Q

How are mycoproteins made

A
  • Produced by Fusarium fungus
  • Grown in glucose syrup in a fermenter
  • In aerobic conditions, the fungus converts the glucose syrup into mycoprotein
  • This biomass is then harvested and purified
29
Q

Advantages of mycoprotein

A
  • Suitable for vegetarians
  • Lots of mycoprotein can be grown in a small amount of space
30
Q

What is a trophic level

A

An organism’s position in a food chain

31
Q

How do decomposers break down dead material

A
  • They secrete enzymes
  • Enzymes partially digest waste proucts into small soluble molecules
  • Waste products are then diffused into the microorganism
32
Q

How may a loss in biodiversity lead to extinction of humans

A
  • Many drugs are derived from plants
  • If plant species are lost, new drugs may not be found/existong drugs will be in low stock
  • Diseases may not be treatable leading to death
  • Pollinators contribute to food chains that produce food we eat
  • Food chains will be disrupted
  • Mass stravation could occur