Life processes in the biosphere Flashcards

1
Q

How do species become better adapted to habitats?

A

Random mutation, natural selection (evolution)

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

What abiotic factors affect species distribution?

A

Light, pH, water and mineral nutrients

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

What biotic factors affect species distribution?

A

Food supply, pollination, seed dispersal and disease

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

What is a taxon?

A

A taxonomic group

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

What is an ecological niche?

A

The role an organism plays in its habitat

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

What is a population?

A

A group of one species occupying a defined area

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

What is a biome?

A

A large geographical region with specific climatic conditions within which a unique community of species lives

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

What is ecological succession?

A

The process of change in the species structure of an ecological community over time

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

What are the stages of ecological succession?

A

A ‘pioneer’ species of extremophiles colonises, the population grows and changes the habitat, making it more suitable for other species and this continues until the climax community develops

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

What is the climax community?

A

The final species to colonise that remains dominant unless the climate changes

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

How do temperature extremes change during ecological succession?

A

High to low

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

How does water availability change during ecological succession?

A

Variable to reliable

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

How do light levels change during ecological succession?

A

High to low

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

How does nutrient availability change during ecological succession?

A

Low to high

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

How do rate of change change during ecological succession?

A

Rapid to slow

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

How does main pollination method change during ecological succession?

A

Wind pollination to insect pollination

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

How does main seed dispersal method change during ecological succession?

A

Wind dispersal to animal dispersal

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

How does the importance of inter-species relationship change during ecological succession?

A

Low to high

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

How does biomass change during ecological succession?

A

Low to high

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

How does biodiversity change during ecological succession?

A

Low to high

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

What are the critical determinants of a biome?

A

Temperature and rainfall

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

What is a sere?

A

The conditions under which the first stages of ecological succession occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the three seres?

A

Hydrosere
Lithosere
Psammosere (sand)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the stages of hydrosere?

A

Pioneer species includes algae and water floating plants
Larger plants colonise in shallow waters
Rooted plants colonise
Marsh plants colonise the margins
Terrestrial plants as soil builds up, water content drops and conditions become more aerobic
Terrestrial plants out compete the water plants and they die out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How are spores and seeds brought into the freshwater?

A

Birds, such as herons and ducks, and flying incests, such as water beetles and pond skaters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How can rooted plants colonise?

A

As other plants die naturally, they leave dead organic matter, that and sediment and soil build up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What trees survive in waterlogged soils?

A

Alder and willow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the stages of lithosere?

A

Simple autotrophs colonise, mosses colonise, grasses and ferns colonise, layers of soil start to build up, larger plants and trees start to colonise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the initial conditions of the lithosere?

A

Bare rock, created by a cliff fall, the retreat of a glacier or volcanic eruption, which is under extreme temperatures with limited water availability and no soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What autotrophs first colonise the lithosere?

A

Lichens and algae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What trees have wind-blown seeds?

A

Birch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What trees have animal dispersed seeds?

A

Oak and beech

33
Q

What are the initial conditions of the psammosere?

A

Minimal plant nutrients, rapid drainage and moving sand make root anchorage difficult

34
Q

What happens when plants succeed in colonising the psammosere?

A

The sand is stabilised, nutrient supplies increase, organic matter builds up and water becomes more available

35
Q

What is plagioclimax?

A

The new climax community created under a change of conditions by humans

36
Q

What human activities disturb climax communities?

A

Ploughing, tree felling and burning

37
Q

What is secondary succession?

A

When the community is destroyed by human activities and the original species recolonise the area and the climax community is eventually re-established

38
Q

When does secondary succession occur?

A

When the original vegetation is destroyed by forest fires, floods, storms, deforestation, grazing and mowing

39
Q

How do extreme environments affect species diversity?

A

Often low

40
Q

At what rate are new species being discovered?

A

20,000 per year

41
Q

How many species are currently named?

A

2 million

42
Q

How many species are estimated?

A

5 to 100 million

43
Q

What are population dynamics?

A

The processes that cause populations to change in size and structure

44
Q

What impacts the death rate of species?

A

Disease, drought, predation and shortage of foods

45
Q

What are r-selected species?

A

Species that can respond to low survival rates, they reach sexual maturity quickly and produce many offspring

46
Q

What are some examples of r-selected species?

A

Mice, locusts and greenflies

47
Q

What are k-selected species?

A

Species that recover slowly from a decline in population

48
Q

What are some examples of k-selected species?

A

Wales, elephants and rhinos

49
Q

What is the ecological importance of high species diversity in an ecosystem?

A

Greater ecological stability, faster recovery from disruption, more resilience to change, because there is a greater range of niches, more complex food web and more species interactions

50
Q

What is the maximum sustainable yield?

A

Estimate of the greatest exploitation that is possible, without causing unsustainable long-term decline in population

51
Q

What needs to be known to calculate the maximum sustainable yield?

A

Death rate, population increase rate, number of offspring, population size and growth rate of individual

52
Q

What density independant factors affect mortality rates?

A

Drought, flood and volcanic eruption

53
Q

What density dependant factors affect mortality rates?

A

Food supply, disease and space

54
Q

What is inter specific competition?

A

Different species compete for the same resource, they may live in harmony or one of the species may take over

55
Q

What is intra specific competition?

A

Competition between the same species for a resource

56
Q

What is an example of inter specific competition?

A

Rainforest monkeys on the fig tree

57
Q

What is an example of intra specific competition?

A

Golden eagles on a deer carcass

58
Q

What resources can organisms compete over?

A

Light, nutrients, breeding sites, nesting sites, mates and food

59
Q

What is carrying capacity?

A

The greatest population that an area can support indefinitely without damaging or over-exploiting the environment

60
Q

What happens as the population of prey fluctuates?

A

The predator population follows the same pattern, as prey increases theres more food so the predator population increases, as prey decreases then predators decrease due to food shortages

61
Q

How does grazing maintain plagioclimax communities?

A

Prevents establishment of taller plants, produces bare ground for germination of wildflowers,

62
Q

How does mowing maintain plagioclimax communities?

A

Removes vegetation that would be removed by grazing, also thorny, stinging or bad-tasting plants

63
Q

How does burning maintain plagioclimax communities?

A

Removes vegetation that would not be eaten by animals and creates open, unshaded areas for the growth of young heather plants

64
Q

What is the management practice for lowland heathland?

A

Grazing or burning

65
Q

What is the management practice for hay meadow?

A

Mowing

66
Q

What is the management practice for wet meadow?

A

Grazing

67
Q

What is the management practice for arable field?

A

Ploughing

68
Q

What is the management practice for garden lawn?

A

Mowing

69
Q

What is the management practice for coppiced woodland?

A

Cutting every 3 to 30 years

70
Q

What is the management practice for upland moorland?

A

Grazing or burning

71
Q

What is the management practice for reed beds?

A

Cutting

72
Q

What does the sigmoidal growth curve show?

A

The growth rate of a population as it approaches its carrying capacity

73
Q

What is the shape of a sigmoidal growth curve?

A

S shaped, like the oxygen dissociation curve

74
Q

Why is there a lag phase on the sigmoidal growth curve?

A

There a few individuals to reproduce

75
Q

Why is there a logarithmic phase on the sigmoidal growth curve?

A

The population grows rapidly as birth rate is higher than death rate, most deaths are caused by density independent factors

76
Q

Why is there a stable and fluctuating phase on the sigmoidal growth curve?

A

Birth rate roughly equals the death rate, density dependent factors stop population growth

77
Q

What are methods of artificial population control?

A

Culling, introduction of predator species, captive breeding

78
Q

What is the biosphere?

A

All of the planet that is inhabited by living organisms, including the land surface, soil, water and atmosphere