Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology A2 Rafa > 6.5 Ecosystems > Flashcards

6.5 Ecosystems Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What are abiotic factors?

A

non-living components of an ecosystem that affect other living organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are biotic factors?

A

environmental factors associated with living organisms in an ecosystem that affect each other. e.g. predation, disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define ecosystem

A

A community of animals, plants and bacteria interrelated with the physical and chemical environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Examples of biotic factors

A
  • producers
  • consumers
  • decomposers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Examples of abiotic factors

A
  • pH
  • relative humidity
  • temperature
  • concentration of pollutants
  • weather, eg storms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why do we refer to ecosystems as dynamic?

A

Because they change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Three types of changes in ecosystems that affect population size?

A
  • cyclic changes (moving tides and changes in day)
  • directional changes (erosion of coastline)
  • unpredictable/ erratic changes (lighting and hurricanes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is biomass transfer?

A

transfer of biomass from one trophic level to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a trophic level?

A

the level at which an organism feeds in a food chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is biomass lost from a food chain?

A
  • lost as heat, CO2 and water

- dead organisms and waste material, only available to decomposers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the area if a pyramid of biomass represent?

A

Its proportional to the dry mass of the organisms at that trophic level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do you calculate the dry mass of an organism?

A

-collect organisms
-oven at 80 degrees until all water has evaporated
(destructive so use wet mass and calculate dry mass on the basis of previously published data)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Equation to calculate the efficiency of biomass transfer between trophic levels?

A

Ecological efficiency = (Biomass at higher trophic level/biomass at lower trophic level) x 100
efficiency=(biomass/ biomass transferred) x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is productivity?

A

The rate of production of new biomass by producers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is gross primary productivity?

A

the rate at which plants convert light energy to chemical energy by photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How can you increase gross primary productivity using light?

A
  • light banks

- crops planted early to provide a longer growing season to harvest more light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Ways to increase gross primary productivity?

A
  • light levels
  • irrigating/ drought resistant crops
  • increasing temp
  • nutrients
  • removing pests
  • removing competition from weeds for light, water and nutrients (herbicides)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How can you increase gross primary productivity using temperature?

A

Greenhouses, increases photosynthesis and rate of production of biomass
-planting crops early to provide a longer growing season helps avoid effect of temperature on final yield

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How can we increase gorss primary production using nutrients?

A
  • crop rotation (growing a different crop in each field of rotational cycle)
  • including nitrogen fixing crop, such as peas or beans replenishes nitrogen levels
  • some crops bred to respond to high levels of fertiliser
20
Q

How does crop rotation help conservation of biomass?

A

Stops reduction in soil levels of inorganic materials such as nitrate or potassium

21
Q

How can we increase gross primary production that is reduced by pests and fungi?

A
  • pesticides
  • some plants have been bred to be pest resistant
  • fungicides
22
Q

How can you increase secondary productivity?

A
  • harvesting animals before adulthood (no loss of energy for growth)
  • selective breeding (fast growth rates)
  • treating with antibiotics (no loss of energy to pathogens and parasites)
  • constant temperatures
  • supplying food
23
Q

Steps of saprotrophic decomposition…

A
  • saprotrophs secrete enzymes onto dead material
  • enzymes digest material into small molecules which are absorbed
  • molecules are stored or respired
24
Q

Examples of fixed nitrogen

A

NH4+ or NO3-

25
Q

Examples of nitrogen fixation

A

Lighting strikes
Haber process
Nitrogen fixing bacteria

26
Q

What are nitrogen fixing bacteria that live in the soil called?

A

Azotobacter

27
Q

Which nitrogen fixing bacteria live in root nodules?

A

Rhizobium

They have a mutualistic relationship with plant, provide nitrogen and receive glucose in return

28
Q

Examples of plants that have rhizobium?

A

peas, beans and clover

members of bean family

29
Q

Difference between habitat and niche

A
  • Habitat is where organism

- Niche is the role an organism fulfils in an ecosystem

30
Q

Define climax community

A

the final stable community that exists after the process of succession has occurs

31
Q

Three types of productivity that I need to be comfortable with

A
  • gross primary productivity (rate at which plants covert light energy into chemical energy)
  • net primary productivity
  • secondary productivity
32
Q

Two main types of nitrogen fixing bacteria

A

Rhizobium and axotobacter

33
Q

Bacteria from ammonium to nitrites

A

nitrosomonas

34
Q

Bacteria from nitrites to nitrates

A

nitrobacter

35
Q

Conditions for denitrification

A

anaerobic

36
Q

Examples of chemoautotrophic bacteria

A

Nitrosomonas and nitrobacter

37
Q

What is deflected succession?

A

Happens when succession is stopped or interfered with, such as by grazing or when a lawn is mowed

38
Q

Define pioneer species

A

the species that begin the process of succession, often colonising an area as the first living things there

39
Q

Define succession

A

A progressive change in a community of organisms over time

40
Q

What is secondary succession?

A

Succession that occurs on previously colonised but disturbed or damaged habitat

41
Q

Example of primary succession

A

On Surtsey in Iceland - formed in 1960s

  • algae and lichens live and die
  • death and erosion of rock makes soil
  • larger plants can grow etc to climax community
42
Q

What is a community called thats sub-climactic?

A

Plagioclimax

43
Q

What does random sampling use?

A

point quadrat/frame (higher up)

quadrate/frame

44
Q

How do you use a point quadrat?

A

Higher up quadrat

You drop pin down and count all plants touching it

45
Q

How can you calculate the total population size using quadrats?

A

total population size = mean number of individuals of the species in each quadrat/fraction of total habitat area covered by a single quadrat

46
Q

Two approaches to using a transect

A
  • Line transect (at regular intervals, make note of which species touching the tape)
  • Belt transect (at regular intervals, place quadrat next to line and move along)

Biology A2 Rafa (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions