Energy Transfer - Energy and Ecosystems Flashcards

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1
Q
A
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2
Q

what is a producer?

A

a photosynthetic organism that manufactures organic substances using the sun’s energy

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3
Q

what is a consumer?

A

An organism that feeds on another organism

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4
Q

what is a trophic level?

A

a stage in a food chain

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5
Q

what are saprobionts?

A

organisms that break down the complex material in dead organisms into simple ones

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6
Q

what is biomass?

A

the total mass of living material in a specific area at a given time

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7
Q

what is a food web?

A

a series of linked food chains

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8
Q

what is a food chain?

A

a linear representation of the feeding relationship in an ecosystem

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9
Q

what is the ultimate source of energy in all ecosystems?

A

sunlight

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10
Q

how is sunlight conserved in plants?

A

as chemical energy

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11
Q

what do most plants use sunlight for?

A

making organic substances, usually sugars

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12
Q

what are the two forms of biomass?

A

fresh mass

dry mass

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13
Q

what is fresh mass?

A

all of the biomass of an organism

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14
Q

what is dry mass?

A

the biomass of an organism when all the water has been removed

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15
Q

what is an advantage of using fresh mass?

A

it is easy to access

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16
Q

what is a disadvantage of using fresh mass?

A

different organisms have varying amounts of water so not representative of the amount of other biological molecules present

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17
Q

what is an advantage of using dry mass?

A

it is more reliable

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18
Q

what are the disadvantages of using dry mass?

A

time consuming

organisms have to be killed

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19
Q

what are the units for biomass?

A

dry mass per given area

eg kg m-2

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20
Q

how can the energy at each trophic level be calculated?

A

collect a sample of the organism

weigh sample

burn in pure oxygen in a sealed chamber called a bomb

measure temp increase in a fixed volume of water

calculate energy released

21
Q

why is energy lost between the sun and a producer?

A

over 90% of sun’s energy reflected into space

not all wavelengths can be absorbed

light may not hit the chlorophyll

22
Q

why is energy lost between the producer and primary consumer?

A

some plant material cannot be accessed (eg roots)

some cannot be digested

excretory losses

respiratory losses

death and decay

23
Q

why is energy lost between consumers?

A

excretory and respiratory losses

indigestible material

movement

death + decay

24
Q

what is gross primary production?

A

the total amount of chemical energy converted from light energy in plants, in a given area

25
Q

what is the equation for net primary production in plants?

A

NPP = GPP - respiration losses

26
Q

what is the equation for npp in animals?

A

NPP = I - (F + R)

or

net primary production = food ingested - (faeces + respiration losses)

27
Q

what is the equation for energy efficiency?

A

energy available after transfer divided by energy available before transfer

then x100

28
Q

what is ammonification?

A

the production of ammonium ions from ammonium containing compounds

29
Q

what carries out ammonification?

A

saprobionts

30
Q

what is nitrification?

A

the production of nitrate ions from ammonium ions

31
Q

what carries out nitrification?

A

nitrifying bacteria

32
Q

what are the stages of nitrification?

A

ammonium ions

nitrite ions

nitrate ions

33
Q

what is nitrogen fixation?

A

converting nitrogen gas into ammonium ions

34
Q

what causes nitrogen fixation?

A

lightning

mutualistic bacteria living in plant root nodules

free living bacteria

35
Q

what is denitrification?

A

converting nitrates into nitrogen gas

36
Q

what causes denitrifiction?

A

anaerobic conditions

denitrifying bacteria

37
Q

what is assimilation?

A

when plants take up nitrate ions from the soil

38
Q

draw a diagram of the phosphorus cycle

A
40
Q

what is guano?

A

accumulation of seabird faeces

41
Q

what assists plants in the absorption of phosphate ions?

A

mycorrhizae

42
Q

what is mycorrhizae?

A

the mutualistic relationship between fungi and the roots of plants where the fungi help absorb minerals for the plant and the plant provides organic compounds for the fungi

43
Q

how do the fungi help increase the uptake of minerals in mycorrhizae?

A

they increase the surface area of the roots of the plant

44
Q

what is eutrophicaton?

A

the prescence of excessive nutrients in a waterway, causing the death of fish and plants

45
Q

why are fertilisers used?

A

in natural ecosystems the minerals removed are returned by dead plants/animals

in farming they are not returned as crops are harvested so need fertilisers to replace lost minerals

46
Q

what is leaching?

A

the washing away of water soluble compounds in the soil

47
Q

what are the types of fertilisers?

A

natural/organic

artificial

48
Q

what do natural/organic fertilisers contain?

A

dead + decaying remains of plants+animals as well as waste such as slurry and manure

49
Q

what do artificial fertilisers contain?

A

pure chemicals as powders or pellets

50
Q
A