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AQA Biology > Ecology > Flashcards

Ecology Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

what is an ecosystem?

A

the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment

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2
Q

what is a habitat?

A

the place where an organism lives

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3
Q

what is a population?

A

all the organisms of one species living in a habitat

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4
Q

what is a community?

A

populations of different species living in a habitat

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5
Q

what do plants compete for?

A
  • light
  • space
  • water
  • mineral ions
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6
Q

what do animals compete for?

A
  • space
  • food
  • water
  • mates
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7
Q

what is interdependence?

A

each species depends on other species for food, shelter, pollination, seed dispersal etc

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8
Q

what do organisms need to survive and reproduce?

A

organisms require a supply of materials from their surroundings and from the other living organisms there

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9
Q

what are the abiotic factors in a community?

A
  • light intensity
  • temperature
  • moisture levels
  • soil pH and mineral content
  • wind intensity and direction
  • carbon dioxide levels for plants
  • oxygen levels for aquatic animals
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10
Q

what are the biotic factors in a community?

A
  • availability of food
  • new predators arriving
  • new pathogens
  • one species outcompeting another so the numbers are no longer sufficient to breed
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11
Q

what type of adaptations do organisms have?

A
  • structural eg. artic fox=white fur, whale=thick layer of blubber (fat)+low SA:V ratio, camel=thin layer of fat+large SA:V ratio
  • behavioural eg. swallow (bird)=migrate
  • functional eg. desert animals=conserve water= very little sweat+small amounts of concentrated urine, brown bear=hibernate=low metabolism=saves energy
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12
Q

what are organisms that live in extreme conditions called?

A

extremophiles eg. bacteria in deep sea vents

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13
Q

what is a food chain?

A

a way of representing feeding relationship in a community

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14
Q

what does a food chain show?

A
  • producers –> eaten by primary consumers –> eaten by secondary consumers –> eaten by tertiary consumers
  • consumers that kill and eat other animals are predators, and those eaten are prey
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15
Q

what is the relationship between predator and prey numbers?

A

In a stable community the numbers of predators and
prey rise and fall in cycles

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16
Q

the water cycle

A
  • energy from sun=evaporates water=water vapour+transpiration
  • water vapour rises=high up=cools+condenses=clouds
  • water falls down as precipitation eg rain, snow, hail=provides freshwater for plants+animals
  • drains into sea
  • repeat
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17
Q

the carbon cycle

A
  • CO2 removed from atmosphere by photosynthesis=glucose= C turned into carbs/fats/proteins=make bodies of plant+algae
  • CO2 returned when plants+algae respire
  • plants+algae eaten=C becomes part of fat/protein
  • C moves through food chain
  • animals respire=C returned to atmosphere
  • plants+algae+animals die=detritus feeders+microorganisms eat them=they respire=CO2 returned atmosphere
  • combustion of wood/fossil fuels=release CO2
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18
Q

what factors affect the rate of decay?

A
  • temp - warm temp=enzymes that work aid in decomposition work quicker
  • enzymes will denature if it’s too hot
  • cold=slows down/stop rate of decomposition
  • oxygen availability - O2 needed for respiration=needed to survive
  • not enough O2=anaerobic decomposition=slow+releases methane
  • water availability - moist environment=faster=decomposers need water to survive=
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19
Q

how is biogas made?

A

by anaerobic decay
- made up of methane
- sludge waste eg. sewage works, sugar factories=large-scale biogas
- x be stored as a liquid=used straight away eg. cooking, heating, power a turbine, lighting

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20
Q

where is biogas made?

A
  • made in a digester/genetor=kept at constant temp= x respiring microorganisms being present
  • batch generator=makes it in small batches=manually loaded up in waste=left to digest+cleared away at the end of each session
  • continuous generator=constantly making=waste continuously fed in=produced on steady rate=large-scale projects
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21
Q

how do gardeners benefit from decomposition?

A
  • they try to provide optimum conditions for rapid
    decay of waste biological material
  • compost produced is used as a
    natural fertiliser for growing garden plants or crops
22
Q

what are examples of environmental changes?

A
  • temperature eg. distribution of plants+animals change between wet and dry seasons
  • availability of water eg. distribution of bird species in germany changes due to rise in temp
  • composition of atmospheric gases eg. distribution of species changes due to air pollution
23
Q

How are the changes caused?

A
  • seasonal
  • geographic
  • caused by human
    interaction
24
Q

what is biodiversity?

A

variety of all the different species of organisms on
earth, or within an ecosystem

25
Q

why is biodiversity important?

A
  • great biodiversity=stability of ecosystems by reducing
    the dependence of one species on another for food, shelter and maintenance of the physical environment
  • future of the human species on Earth relies on us maintaining
    a good level of biodiversity but human activities are reducing
    biodiversity and only recently have measures been taken to try to stop this
26
Q

why do we have more waste?

A
  • rapid growth in population and an increase in the standard
    of living=more resources are used=more waste is produced
27
Q

what factors affect pollution?

A
  • water, from sewage, fertiliser or toxic chemicals eg. pesticides=pollute rivers+oceans=affect plant+animal relying on them to survive
  • air, from smoke and acidic gases=pollute air eg SO2=acid rain
  • land, from landfill sites (household waste)/toxic chemicals/farming eg. herbicides+burying nuclear waste=pollute soil=x grow crops

Pollution kills plants and animals which can reduce biodiversity.

28
Q

how do we use land?

A
  • building
  • quarrying
  • farming
  • dumping waste
    =less land for other animals+plants
29
Q

what does the destruction of peat bogs lead to?

A
  • x enough O2 for plants in peat x fully decay=CO2 stored in peat
  • drained=farmland or used as fuel or sold to gardeners as compost
  • when drained=contact with air=microorganisms decompose it+respire=use O2+release CO2
  • when burned=CO2 released
  • destroying peat bogs=x habitats for animals/plants= reduces biodiversity
30
Q

what does peat release?

A

CO2

31
Q

what is deforestation used for?

A
  • provide land for cattle and rice fields
  • grow crops for biofuels
32
Q

what are the disadvantages of deforestation?

A
  • less trees=less CO2 used for photosynthesis=more in atmosphere as trees decay+microorganisms eat them=release CO2 from respiration
  • CO2 released when trees are burnt
  • trees=habitat for animals/plants=tress cut down=less biodiversity=risk of extinction
33
Q

what are the consequences of global warming?

A
  • higher temp=sea water expands+ice melts=sea level up=flooding=loss of habitats
  • higher temp=rainfall patterns change=distribution of animals+plants will change eg. animals living in hot temp widely distributed
  • changes in migration patterns eg birds migrate further north as nothern areas are getting warmer
  • some species unable to survive with temp change=extinct=less biodiversity
34
Q

how can we maintain biodiversity?

A
  • breeding programmes for endangered species=x extinction
  • protection and regeneration of rare habitats eg. coral reefs=protect ecosystem+biodiversity
  • reintroduction of field margins and hedgerows in agricultural areas=habitat for wider variety of species
    where farmers grow only one type of crop
  • reduction of deforestation and carbon dioxide emissions by governments=reduce global warming
  • recycling resources rather than dumping waste in landfill=reduces waste=reduces land used in landfill=ecosystems x destroyed
35
Q

what are issues with maintaining biodiversity?

A
  • costs money eg gov pay farmers to a subsidy to reintroduce hedgerows or to keep watch the programmes are being followed –> money prioritised for other things
  • affects locals eg. reducing deforestation=people working in tree-felling unemployed=local economy affected
  • protecting food security=pests eg. fox, locust=killed to protect crops/livestock=more food=food chain+biodiversity affected
36
Q

what are trophic levels?

A

different stages of a food chain

Level 1: producers
Level 2: primary consumers
Level 3: secondary consumers.
Level 4: tertiary
consumers

37
Q

what are apex predators?

A

carnivores with no predators
- top of food chain=highest trophic level

38
Q

what do decomposers do?

A
  • break down dead plant and animal matter by secreting
    enzymes=small soluble food molecules=diffuse into microorganism
39
Q

what do pyramids of biomass show?

A
  • represent the relative
    amount of biomass in each level of a food chain (how much the organisms weigh)
  • trophic level 1 is at the
    bottom of the pyramid
40
Q

how is biomass transferred?

A
  • 1% of light transferred for photosynthesis=glucose=makes biological molecules=plant’s biomass=stores energy
  • when organisms eat each other=10% of biomass transferred at each level in a food chain
41
Q

why is biomass lost?

A
  • not all the ingested material is absorbed= what isn’t absorbed=egested as faeces
  • some absorbed material is lost as waste eg. lots of glucose from respiration=used to keep warm+movement=x making more biomass=CO2+H2O released & urea+water in urine
42
Q

biomass efficiency equation

A

(biomass in next level/biomass in previous level)x100

43
Q

what is food security?

A

having enough food to feed a population

44
Q

what factors affect food security?

A
  • the increasing birth rate has threatened food security in some
    countries
  • changing diets in developed countries=scarce food resources
    are transported
  • new pests and pathogens that affect farming
  • environmental changes that affect food production eg. widespread famine in some countries=x rain
  • the cost of agricultural inputs eg. price of seeds=too expensive to produce food=less people producing food=less food
  • conflicts=affect the availability of water or food
45
Q

how can farming techniques be improved?

A
  • reducing energy transfer from animals to environment=limiting movement+keeping them in a temp-controlled environment=more energy for growth=more food for same resources
  • livestock+fish=factory farmed=kept in cages/small pens
  • feeding animals high-protein=increase growth
46
Q

pros and cons of farming techniques

A

pros
- effective
- less resources used=saves money
- more food=less food insecurity

cons
- disease can be spread easily=animals kept so close
- animals live in unnatural+uncomfortable conditions=cruel
- money saved=used to maintain temp or buy pens/cages

47
Q

what are the effects of fish stocks declining?

A
  • less fish to eat
  • ocean’s food chain affected
  • some fish may disappear
48
Q

how can we fish sustainably?

A
  • fishing quotas=limits number+size of fish caught in certain areas=prevents species being over-fished
  • net size=limits on mesh size of net (big holes)=reduces amount of unwanted/discarded fish=bigger mesh size=unwanted fish escape
  • younger fish escape=can reach breeding age
49
Q

how is biotechnology used?

A

mycoprotein
- a protein-rich food suitable for vegetarians eg. Quorn
- fungus, fusarium=grown on glucose syrup, in
aerobic conditions
- biomass is harvested and purified=produce mycoprotein

bacteria producing human insulin
- plasmid removed from bacterium
- insulin gene cut out from chromosome with a restriction enzyme=leaves sticky ends (unpaired bases)
- plasmid cut open with same restriction enzyme=leaves same sticky ends
- plasmid+human insulin gene sticky ends joined by ligase=recombinant DNA
- recombinant DNA inserted into bacterium
- modified bacterium grown in a vat in controlled conditions
- lots of bacteria that produce insulin=insulin harvested+purified

GM crops=more food or food with an improved nutritional value such as golden rice

50
Q

pros and cons of biotechnology

A

pros
- GM crops=can be resistant to pests/grow better in droughts=better crop yields
- GM crops=more nutritional value=golden rice=chemical that’s converted into vitamin A in the body

cons
- fear that countries are dependent on GM crop companies
- poor soil=crops failing=even GM crop x survive
- people go hungry because they can’t afford food, x because there isn’t food=tackle poverty first

AQA Biology (7 decks)

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