Ecosystems and the biosphere Flashcards Preview

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Flashcards in Ecosystems and the biosphere Deck (87)
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1
Q

Ecosystem

A

communities and their abiotic environment

2
Q

energy flow

A

passage of energy in a one way direction thru an organism

3
Q

Where does energy flow start?

A

enters as sunlight

4
Q

producers

A

organisms that perform photosynthesis

5
Q

How much energy do producers use? From where? What happens to rest?

A

only 1% of energy from sun–rest reflected as heat or light

6
Q

Where is energy stored in producers? Form?

A

chemical form–bonds of organic molecules such as glucose

7
Q

organic

A

C bonded to C

8
Q

Glucose is converted to example of what other forms within producer? Why?

A

ATP; used for work

9
Q

What happens while work is accomplished (glucose)?

A

energy escapes as heat energy

10
Q

food chain

A

energy from food passes from one organism to the next in a sequence as they’re eaten

11
Q

food web

A

interconnected food chains in ecosystem

12
Q

what does food web show?

A

members of each trophic level–arrows go from what’s eaten to what eats it

13
Q

trophic level

A

eating level

14
Q

Level 1: Food Web

A

Producers convert energy from sun into chemical energy–glucose

15
Q

Level 2: Food Web

A

primary consumers–herbivores which eat plants and obtain the energy from the producers’ molecules

16
Q

Level 3: Food Web

A

secondary consumers–primary carnivores which eat the herbivores, obtaining the energy stored in primary carnivores

17
Q

Level 4: Food Web

A

tertiary consumers–secondary carnivores which eat the primary carnivores

18
Q

Level 5: Food Web

A

Decomposers (detritivores)–obtain their energy by consuming
dead plants and animals
usually bacteria, earthworms,

19
Q

Ecological pyramids

A

used to show the relationship between trophic levels

Pyramids can show energy, biomass, or number of organisms

20
Q

Pyramid of numbers

A

shows the number of organisms at each trophic level

in an ecosystem–most pyramids have fewer organisms occupying each successive trophic level,

21
Q

Ex of pyramid of numbers

A

in African grasslands, number of herbivores (zebras) is

greater than number of carnivores (lions)

22
Q

Inverted pyramid of numbers

A

higher trophic levels have more organisms

23
Q

ex of pyramid of numbers inverted

A

Ex- One tree (producer) provides food for thousands of insects (herbivore)

24
Q

Pyramid of biomass

A

shows total biomass (estimate of total mass of living

material) at each successive level

25
Q

Pyramid of energy-

A

indicates the energy content (kc/ m2/ year) of the

biomass of each level

26
Q

Energy pyramids always have what sizing? Why?

A

Energy pyramids always have large bases and get progressively
smaller through succeeding trophic levels, because some energy is lost during each transfer and used by that organism

27
Q

Ecological efficiency

A

describes the proportion of energy represented

at one trophic level that is transferred to the next level

28
Q

What’s the usual ecological efficiency?

A

Usually, only 10% of the energy is transferred

29
Q

cellular respiration

A

uses food for energy

30
Q

productivity

A

how efficient it is with organic compounds. only measuring with producers (so really measuring how much photosynthesis is happening and how much being passed on as opposed to being used in cellular respiration)

31
Q

Gross primary productivity (GPP)

A

rate at which energy is captured during photosynthesis by producers in a given ecosystem (or rate of organic compounds being produced)

32
Q

Net primary productivity (NPP)

A

energy that remains in plant tissues after

cellular respiration has occurred

33
Q

Find Net primary Productivity

A

Gross primary - Plant respiration

Productivity

34
Q

What does NPP represent?

A

NPP represents rate at which the organic material is actually
incorporated into plant tissues to produce growth

35
Q

What energy out of productivity is available to consumers?

A

Only energy of NPP is available for consumers

36
Q

gauging primary productivity in aquatic ecosystem

A

Since oxygen is a product of photosynthesis, to measure the dissolved oxygen. We can then convert the amount of oxygen into mg of carbon fixed by using the calculations below.

37
Q

carbon fixed

A

=amount of carbon that went from CO2 to carbon compounds. fixation–turning one to the other.

38
Q

Calculate carbon fixed (PP)

A

GPP mg O2/L * .698 = mL O2 / L * .536 = mg carbon fixed/L

39
Q

measuring NPP

A

measuring the O2 production in light bc both photosynthesis and respiration are occurring. amount of O2 found in light (after time pd)-amount of O2 found initially

40
Q

measuring amount of O2 being used by respiration

A

by measuring the amount of O2 used in the ecosystem in the dark bc then no photosynthesis will occur.

41
Q

gross productivity measurement

A

Here, you are taking the amount of O2 produced during net

productivity and adding the amount of oxygen lost during respiration

42
Q

measuring gross productivity equation

A

amount of dissolved oxygen found in the light after given amount of time minus the amount of dissolved oxygen found in dark after given amount of time (bottle-dark or NPP + respiration)

43
Q

measuring amount of O2 being used by respiration

A

amount of dissolved oxygen found initially - amount found in the dark (initial-dark)

44
Q

NPP measure equation

A

amount of O2 found in light (after time pd)-amount of O2 found initially
(bottle-initial)

45
Q

what do you need to know to measure productivity

A

knowing initial amount of O2 present

46
Q

unit for productivity

A

mg O2/L

47
Q

factors of productivity

A

Efficiency of carbon fixation o Availability of solar energy, nutrient minerals, and water o Climate factors o Human modification of the environment

48
Q

Biogeochemical cycles

A

shows how matter moves from

one part of an ecosystem to another

49
Q

Carbon cycle

A

movement of carbon between abiotic factors (atmosphere

and ocean) and organisms

50
Q

Carbon cycle step 1

A

Photosynthesis in plants, algae, and cynaobacteria remove CO2 from
the atmosphere and incorporate it into
organic compounds like glucose

51
Q

Carbon cycle step 2

A

Cellular respiration by these producers or by consumers that eat the
producers returns the CO2 to the atmosphere from the
organic compound

52
Q

What have a large storage of carbon compounds?

A

trees, Fossil fuels such as coal, oil, and natural gases formed from the
remains of ancient organisms, limestone

53
Q

Combustion

A

Burning–returns the carbon from trees and fossil fuels
back to the atmosphere in the form of
CO2

54
Q

Limestone

A

sedimentary rock, is made from shells of dead marine

organisms

55
Q

When is CO2 released into air or water

A

when rock is eroded

56
Q

Nitrogen cycle

A
atmospheric nitrogen (78% of atmosphere) is very stable, so
it must first be broken apart before organisms can use it
57
Q

nitrogen fixation

A
Gaseous nitrogen (N2) from the atmosphere is converted into
ammonia (NH3)
58
Q

What performs nitrogen fixation?

A

nitrogen-fixing bacteria

59
Q

Where do nitrogen-fixing bacteria live?

A

nodules of plants

60
Q

cyanobacteria

A

fix nitrogen in aquatic environment

61
Q

nitrification

A

convert the ammonia into nitrates- NO3-

62
Q

Nitrifying bacteria

A

performs nitrification

63
Q

assimilation

A

absorb NH3, NH4+, NO3-
formed and incorporate the nitrogen into
proteins, nucleic acids, and chlorophyll

64
Q

When does assimilation occur?

A

post nitrification

65
Q

When does nitrification occur?

A

post nitrogen fixation

66
Q

Denitrifying bacteria

A

can convert the nitrogen compounds back into

gaseous nitrogen

67
Q

denitrification

A

reduction

of NO3- to N2 (atmospheric nitrogen)

68
Q

Phosphorous cycle

A

cycles from land to ocean and back to land (none in the

atmosphere)

69
Q

Phosphorous cycle step 1

A

Water runs over rocks containing phosphorous, carrying off
inorganic phosphates
PO4(3-)

70
Q

Phosphorous cycle step 2

A

Phosphate enters the soil where it is taken up and

used by plants

71
Q

How do animals obtain phosphorus

A

eating the plants

72
Q

what happens to phosphorus when the animal bodies containing it die

A

the phosphorous is released by decomposers and

reenters the soil

73
Q

What happens to Dissolved phosphorous

A

Dissolved phosphorous enters aquatic ecosystems and is taken up by
algae and other plants, which larger organisms consume

74
Q

What happens when inorganic phosphorus is released by decomposers into water?

A

Phosphate may be deposited on sea floor- geologic processes lift it up
where it can be eroded.

75
Q

Hydrologic cycle

A

water circulates from the ocean to the atmosphere to the

land and back to ocean

76
Q

evapo/transpiration

A

water evaporation from plants- adds more

water vapor to atmosphere

77
Q

How does water move from atmosphere to land

A

Water moves from atmosphere to land and ocean as

precipitation

78
Q

What happens when water evaporates from oceans, streams, rivers, lakes ?

A

condenses and enters the atmosphere as

clouds

79
Q

runoff

A

when water flows from land to ocean

80
Q

estuaries

A

areas where fresh water meets ocean

81
Q

What happens when water seeps down into soil

A

Water also seeps down in soil to become groundwater, where it is
held- eventually supplies water to soil streams rivers plants and oceans

82
Q

biomass

A

estimate of total mass of living

material

83
Q

assimilation performed by

A

Roots of plants

84
Q

step 3 phosphorus cycle

A

animals may eat the plants

85
Q

step 1 nitrogen cycle

A

nitrogen fixation

86
Q

denitrification happens when?

A

post assimilation or nitrification, depending on whether the plants assimilate it

87
Q

Nitrogen cycle

A

Nitrogen fixation turns it into ammonium in soil, then it is nitrified into nitrates. It can either immediately be denitrified back to atmospheric N2, or it can be assimilated by plants and then used as amino acids and proteins in plants and animals. If so, the detritivores will decompose the organism when it dies and send to nitrogen back to soil ammonium.