Topic 7 - Ecology Flashcards
(85 cards)
1
Q
What is an ecosystem?
A
The interaction of a community of living organisms (biotic) with the nonliving (abiotic) parts of their environment
2
Q
Define biotic
A
Living organisms
3
Q
Define abiotic
A
Nonliving
4
Q
What do organisms require in order to survive and reproduce?
A
Supply of materials from their surroundings and from the other living organisms there
5
Q
What do plants in a community or habitat often compete for?
A
Light and space, water and mineral ions from the soil
6
Q
What do animals in a community or habitat often compete for?
A
Food, mates and territory
7
Q
Within a community what does each species depend on another species for?
A
Food, shelter, pollination and seed dispersal
8
Q
What is interdependence?
A
If one species is removed from a community, it can affect the whole community
9
Q
What is a stable community?
A
Where all the species and environmental factors are in balance so that population sizes remain fairly constant
10
Q
What are the abiotic factors which can affect a community?
A
- light intensity
- temperature
- moisture levels
- soil pH and mineral content
- wind intensity and direction
- carbon dioxide levels for plants
- oxygen levels for aquatic animals
11
Q
What are the biotic factors that can affect a community?
A
- food availability
- new predators
- new pathogens
- one species outcompeting another so the numbers are no longer sufficient to breed
12
Q
What are adaptations?
A
Features that allow organisms to survive in the conditions which the normally live
13
Q
What are the three types of adaptation?
A
- structural
- behavioural
- functional
14
Q
Give examples of extreme environments.
A
- high temperature
- high pressure
- high salt concentration
15
Q
What are extremophiles?
A
Organisms that live in extreme environments
16
Q
Give an example of an extremophile.
A
Bacteria living in deep sea vents
17
Q
How can feeding relationships within a community be shown?
A
Food chains
18
Q
What do all food chains start with?
A
A producer which synthesises molecules - usually a green plant or alga which makes glucose by photosynthesis
19
Q
What are experimental methods using transects and quadrants used for?
A
Used by ecologists to determine the distribution and abundance of species in an ecosystem
20
Q
What are producers eaten by?
A
Primary consumers
21
Q
What are primary consumers eaten by?
A
Secondary consumers
22
Q
What are secondary consumers eaten by?
A
Tertiary consumers
23
Q
What is a predator?
A
Consumers that kill and eat other animals
24
Q
What is prey?
A
Animals that are eaten by predators
25
What happens to the numbers of predators and prey in a stable community?
They rise and fall in cycles
26
Why are all materials in the living world recycled?
To provide building blocks for future organisms
27
What does the carbon cycle do?
It returns carbon from organisms to the atmosphere as carbon dioxide to be used by plants in photosynthesis
28
What does the water cycle do?
It provides freshwater for plants and animals on land before draining it into the seas through continuous evaporation and precipitation
29
What affects the rate of decay?
Temperature, water and availability of oxygen
30
What do you gardeners and farmers try to provide optimum conditions for?
Rapid decay of waste biological material
31
What is the compost produced by decay used for?
And natural fertiliser for growing garden plants or crops
32
What does anaerobic decay produce?
Anaerobic decay produces methane gas
33
What can be used to produce methane gas as a fuel?
Biogas generators
34
How does temperature affect the rate of decay?
Warmer temperatures make things decompose quicker because they increased the rate that the enzymes involved in decomposition work at
35
How does oxygen availability affect the rate of decay?
Many organisms need oxygen to respire which they need to do to survive but the micro organisms involved in anaerobic decay don’t need oxygen
36
How does water availability affect the rate of decay?
Decay takes place faster in moist environment because the organisms involved in decay need water to carry out biological processes
37
What are the environmental changes that affect the distribution of species in an ecosystem?
Temperature, availability of water and composition of atmospheric gases
38
What are the three types of environmental changes that affect the distribution of species in an ecosystem?
Seasonal, geographic or caused by human interaction
39
What is biodiversity?
Variety of all the different species of organisms on Earth or within an ecosystem
40
How does a good biodiversity ensure the stability of ecosystems?
By reducing the dependence of one species or another for food, shelter and the maintenance of the physical environment
41
What does the future of the human species on earth rely on?
Us maintaining a good level of biodiversity, as many human activities are reducing biodiversity and only recently measures have been taken to try to stop this reduction
42
What has rapid growth in the human population and an increase in the standard of living lead to?
Increasingly more resources are used and more waste is produced
43
Unless waste and chemical materials are properly handled, what will happen?
More pollution will be caused
44
Where can pollution occur?
Water, air or land
45
How is pollution created in water?
From sewage, fertiliser or toxic chemicals
46
What pollution is in the air?
From smoke and acidic gases
47
What causes pollution on land?
From landfill and from toxic chemicals
48
How does pollution affect living organisms?
Pollution kills plants and animals which can reduce biodiversity
49
How do humans reduce the amount of land available for other animals and plants?
By building, quarrying, farming and dumping waste
50
What reduces the area of the habitat?
The destruction of peat bogs, and other areas of peat to produce garden compost
51
What does reducing the area of a habitat also reduce?
The variety of different plant, animal and microorganisms species that live there (by diversity)
52
What does the decay or burning of peat release?
Carbon dioxide into the atmosphere
53
What has large-scale deforestation in tropical areas occurred for?
- To provide land for cattle and ricefields
| - to grow crops for biofuels
54
What contributes to global warming?
Levels of carbon dioxide and methane in the atmosphere are increasing
55
What are the biological consequences of global warming?
- Higher temperatures causing ice to melt and flooding
- change to the distribution of wild animal and plant species as temperature changes
- changes in migration patterns
- biodiversity could be reduced
56
What have scientists and concerned citizens put programs in place for?
To reduce the negative effects of humans on ecosystems and biodiversity
57
What are the programs that scientists and concerned citizens have put in place to reduce the negative affects of humans on ecosystems and biodiversity?
- breeding programs for endangered species
- protection and regeneration of rare habitats
- reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
- reduction of deforestation and carbon dioxide emissions by some governments
- recycling resources rather than dumping waste in landfill
58
How can trophic levels be represented?
By numbers starting at level one with plants and algae
59
How are further trophic levels numbered?
Subsequently according to how far the organism is along the food chain
60
What is trophic level 1?
Plants and algae make their own food and are called producers
61
What is trophic level two?
Herbivores eat plants or algae and are called primary consumers
62
What is trophic level three?
Carnivores that eat herbivores are called secondary consumers
63
What is trophic level four?
Carnivores that eat other carnivores are called tertiary consumers
64
What is apex predator?
Carnivores with no predators
65
What do decomposes do?
Decomposers break down dead plant and animal matter by secreting enzymes into the environment, small soluble food molecules then diffuse into the microorganism
66
What are pyramids of biomass?
They are diagrams that are constructed to represent the relative amount of biomass in each level of a food chain
67
What is the bottom level of a pyramid of biomass?
Trophic level one
68
How much energy does a producer transfer to the primary consumer?
About 1% of the incident energy from light for photosynthesis
69
How much of the biomass from each trophic level is transferred to the level above it?
About 10%
70
What are losses of biomass due to?
- not all the ingested material is absorbed, some is egested as faeces
- some absorbed material is lost as waste, such as carbon dioxide and water in respiration and water and urea in urine
71
What is used in large amounts during respiration?
Large amounts of glucose are used in respiration
72
How do you calculate efficiency of biomass transfer?
Efficiency = biomass transferred to next level / biomass available at previous level x 100
73
What is food security?
Having enough food to feed a population
74
What are the biological factors that are threatening food security?
- The increasing birthrate
- changing diet in developed countries mean scarce food resources are transported around the world
- New pests and pathogens that affect farming
- environmental changes that affect food production, such as widespread famine
- The cost of agricultural inputs
- conflicts that have arisen in some parts of the world which affect the availability of food or water
75
What must be done in order to feed all people on earth?
Sustainable methods must be found
76
How can the efficiency of food production be improved?
By restricting energy transfer from food animals to the environment
77
How do you restrict energy transfer from food animals to the environment?
By limiting their movement and controlling the temperature of their surroundings
78
Why are some animals fed high-protein foods?
To increase growth
79
Why is it important to maintain fish stocks at a level where breeding continues?
Fish stocks in the oceans are declining and certain species may disappear altogether in some areas
80
How do we conserve fish stocks at a sustainable level?
Controlling the sizes of nets and introducing fishing quotas
81
What do modern biotechnology techniques enable?
Large quantities of microorganisms to be cultured for food
82
What is the fungus fusarium useful for?
Producing micro protein, a protein rich food suitable for vegetarians
83
How is the fungus fusarium grown?
On glucose syrup, in aerobic conditions, and the biomass is harvested and purified
84
How is genetic modification a good biotechnology technique?
A genetically modified bacteria produces human insulin, which when harvested and purified it is useful to treat people with diabetes
85
What can GM crops provide?
More food or food with an improved nutritional value such as golden rice
