Brainscape's Knowledge GenomeTM

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


See full index

A Level Bio unit 3 > Population > Flashcards

Population Flashcards

1
Q

Teen population

A

A group of organisms of the same species

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

Population numbers increase because of

A

Birth and immigration

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

Population numbers decrease because of

A

Death and emigration

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

In stable population

A

Birth + immigration = deaths + emigration

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

Density dependent

A

Abiotic - living
Affect greater proportion of population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Density independent

A

Biotic - non living

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

Term carrying capacity

A

Maximum number of individuals of species that the environment can support indefinitely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Phases of population growth

A

LAG
LOG
STATIONARY
DEATH

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

Lag (yeast)

A

Enzymes are synthesised
Dna is replicated

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

Log ( yeast)

A

Population doubles every unit of time
Nutrients abundant

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

Stationary ( yeast)

A

Competition of nutrients means death and cell reproduction happen at the same time

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

Death ( yeast)

A

Nutrient depletion and toxin accumulation mean death rate is higher than cell reproduction

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

Ecosystem

A

An area that has a particular community of plants and animals interacting with their environment

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

Term community

A

All of the organisms of all species in an ecosystem

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

Term habitat

A

Place in the ecosystem where organisms live

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

Term niche

A

An organisms role in ecosystem
Applies particularly to their feeding role

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

Photoautrophs

A

Mainly green plants
Use light energy from the sun to fix carbon dioxide into organic molecules by photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

GPP - R= NPP

A

Gross and net primary productivity

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

Why is some energy never taken in at each trophic level

A

Some parts of food aren’t consumed
Some parts of food indigestible
Plants can’t use all light energy as some is the wrong wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is some energy lost at each trophic level

A

Respiration
Lost as heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Pyramid of biomass

A

A table of dry mass of living material at each trophic level of a food chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Gross primary productivity

A

The rate of chemical energy fixture during photosynthesis by all producers in an ecosystem

23
Q

Net primary productivity

A

The amount of chemical energy that is available to the heterotrophs in an ecosystem

24
Q

How to calculate net primary productivity

A

Gross primary - respiratory losses

25
Q

Term succession

A

Is the change in structure and species of a community overtime

26
Q

Term secondary succession

A

Starts from cleared land where communities have lived before
It is faster as there are seed roots and soil to support the plants
Happens after forest fires or tree felling

27
Q

Term Sere

A

Each stage of succession

28
Q

How is succession depleted

A
  1. Mowing
  2. Burning
  3. Grazing
29
Q

Term primary succession

A

Starts from bare rock where no organisms lives

30
Q

What are pioneer species

A

Species that can survive in hostile environments and colonise bare rock
Eg
Lichens

31
Q

Process of primary succession

A
  1. Pioneer species colonise the area
  2. They die decompose and add nutrients to the ground
  3. Over time this allows more complex organisms to survive
32
Q

Climax community

A

Final stage of succession where ecosystem is balanced and stable

33
Q

What does succession increase

A
  1. Species diversity
  2. Stability of community
34
Q

Risk assessment of investigation

A
  1. Biting insects
  2. Stinging plants
  3. Cover skin
  4. Use insect repellent
    Weather conditions -
  5. Sunburn
  6. Hypothermia
35
Q

Representative sampling

A

Use the correct size grid/quadrant for area
Carry out enough repeats

36
Q

Carbon cycle

A
  1. Plants take in CO2 and use it in photosynthesis to make organic molecules passed through food chains
  2. Plants and animals respite and excrete CO2
  3. Combustion releases CO2
  4. Decomposes respire excreting CO2
  5. Formation of fossil fuels
37
Q

Autotrophs

A

Use energy from sunlight or chemicals to convert inorganic compounds into organic ones
Organic compounds are passed along food chains

38
Q

Decomposers

A

Use organic molecules and convert them to inorganic compounds

39
Q

Human impact on carbon cycle

A
  1. Deforestation
  2. Combustion
  3. CO2 greenhouse gas
  4. Global warming
  5. Agricultural practises
40
Q

What does deforestation do

A

It removed trees so less photosynthesis takes place so less CO2 is absorbed from the atmosphere

41
Q

What does combustion do

A

Combustion of fossil fuels and wood releases locked in CO2 to the atmosphere

42
Q

Greenhouse gas on carbon cycle

A

Traps heat and raises global temperatures therefore causing global warming

43
Q

Global warming on carbon cycle

A

Affects species distribution as regions further up north and south of the equator are warmer

44
Q

Decomposition rate is affected by

A

Temperature - slower when cold
pH - slower when acidic
O2 availability - slower when less oxygen available

45
Q

Carbon footprint

A

Is the total amount of CO2 released attributable to an individual, product or service over the course of a year

46
Q

Water logged soils

A

Lack o2 this favours denitrification and slows nitrification
This leads to nitrate poor soil
- ploughing introduces air into soil
- drainage ditches reduce water logging and denitrification

47
Q

Nitrifying bacteria

A

Nitrosomonas
Nitrobacter

48
Q

Nitrosomonas

A

Convert ammonium to nitrite

49
Q

Nitrobacter

A

Convert nitrite to nitrate

50
Q

Nitrogen fixing bacteria

A

Convert nitrogen gas to ammonium
Azotobacter
Rhizobium

51
Q

Azotobacter

A

Free living in soil

52
Q

Rhizobium

A

In root nodules of legumes symbiotic

53
Q

Denitrifying bacteria
Convert nitrate to nitrogen gas

A

Pseudomonas - thrive in water logged soils

A Level Bio unit 3 (9 decks)

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