Topic 9 - Ecosystems and Interactions Between Organisms Flashcards
(152 cards)
1
Q
List the different levels of organisms
A
Individual
Population
Community
Ecosystem
2
Q
What is an individual?
A
A single organism
3
Q
What is a population?
A
All the organisms of one species in a habitat
4
Q
What is a community?
A
All the organisms of different species living in a habitat
5
Q
What is an ecosystem?
A
A community of organisms along with all the non-living conditions
6
Q
What does abiotic mean?
A
Non-living
7
Q
What do organisms need?
A
Food
Shelter
8
Q
What is the definiton of interdependence?
A
Organisms depending on each other for food, shelter and reproduction
9
Q
Give types of interdependent relationships?
A
Mutualism
Parasites
10
Q
What is mutualism?
A
A relationship where two organisms both benefit
11
Q
What is a parasite?
A
An organism which survives and takes what it needs from the host without it benefitting
12
Q
Give examples of abiotic factors
A
Temperature
Amount of water
Light intensity
Pollution
13
Q
Give examples of biotic factors
A
Competition
Predation
14
Q
Give two abiotic factors that could affect the community in an ecosystem
A
Any two from: Temperature Amount of water Light intensity Pollution
15
Q
What is a habitat?
A
A place where an organism lives
16
Q
What is a species?
A
A group of similar organisms that can reproduce to give fertile offspring
17
Q
What do you use to study the distribution of small organisms?
A
Quadrats
18
Q
What is a quadrat?
A
A square frame enclosing a known area
19
Q
Briefly describe how to study the distribution of small organisms
A
Randomly measure bits of the area
Work out the mean number of small organisms
20
Q
How do you estimate population size?
A
Population = Mean number of organisms x Area
21
Q
How can you study distribution along a gradient?
A
By using a belt transect
Mark out the line and measure along it, collect the data
Then calculate the mean amount
22
Q
What is the source of energy for all food chains?
A
The Sun (light)
23
Q
How does light get into the food chains?
A
Enters the plants through photosynthesis which is then converted into glucose
The glucose is then either used or stored and passed along the chain as biomass
24
Q
What is biomass?
A
The mass of living material that makes up an organism
25
How do plants lose energy on the food chain?
By using the glucose for respiration
26
How do animals lose energy on the food chain?
Life processes (eg. movement)
Heating
Respiration
27
Why doesn't the energy released by respiration get passed along the chain?
Because the energy isn't stored as biomass
28
What is each stage of a food chain called?
A trophic level
29
Why isn't all the energy passed through the chain?
Life processes
Not all the animal is eaten (eg. Bones)
Not all the animal can be digested
30
What does a pyramid of biomass show?
How much the creatures at each level of a chain would weigh if you put them together
31
What happens each time you go up one trophic level?
Less number and mass of organisms
32
What must you remember when drawing a pyramid of biomass?
Draw to scale
Producer is always at the bottom
Include the weight of the organisms
33
Give two reasons why much of the energy in one trophic level is not passed on the next
Any two from:
Not all organism is digested
Not all organism can be eaten (eg. Bones)
Organism 'wasted' energy on life processes
34
Calculate the energy lost between the first and second trophic levels
Rosebush = 80,000 kJ
Greenflies = 10,000 kJ
= 80,000 - 10,000
| = 70,000 kJ lost
35
What is the efficiency equation?
Efficiency = (Energy transferred to next level) / (Energy available at previous level) x 100
36
Calculate the efficiency of the energy transfer between the first and second trophic levels?
Rosebush = 80,000 kJ
Greenflies = 10,000 kJ
= (10,000 / 80,000) x 100
| = 12.5%
37
Calculate the energy transfer between the second and third trophic levels?
Hoverfly larvae = 850 kJ
Bird = 80 kJ
= 850 - 80
| = 770
38
What is biodiversity?
The variety of living organisms of living organisms in an ecosystem
39
Why are nitrates added to fields?
To fertilise the field
40
What is eutrophication?
An excess of nutrients in water
41
Describe the process of eutrophication?
Excess fertilisers enter the water adding nitrates which causes algae to grow fast and block out the light
Because of the lack of light, plants can't photosynthesise so they start to decompose
This provides more food to microorganisms which feed and breed taking up oxygen in the water
This causes fish to die
42
How does fish farming reduce biodiversity?
Food produces waste which causes eutrophication
Parasites can be produced
Fish can escape and can cause problems
43
What is a non-indigenous species?
A species that doesn't naturally occur in that area
44
How can non-indigenous species be introduced?
Intentionally
| Unintentionally
45
Why do non-indigenous species cause problems?
Can outcompete indigenous species
| Can bring diseases
46
Suggest how introducing a non-indigenous species could reduce the biodiversity of an area?
By outcompetiting indigenous species or by bringing diseases
47
What ways are there to conserve and maintain biodiversity?
Reforestation
| Conservation schemes
48
What is reforestation?
The replanting of new trees
49
What do conservation methods include?
Protecting a species' natural habitat
Protecting species in safe areas
Protecting seeds in a seed bank
50
What are the benefits of maintaining biodiversity?
```
Protecting the human food supply
Ensuring minimal damage to food chains
Providing future medicines
Cultural aspects
Ecotourism
Providing new jobs
```
51
Explain how reforestation affects biodiversity
Provides more food and shelter for different animal species
52
What factors affect the level of food security?
```
Increasing human population
Increasing consumption of meat and fish
Environmental changes caused by human activity
Sustainability
New pests and pathogens
```
53
Why is eating plants better than meat (biologically)?
Plants are the begining of the food chain meaning they have more biomass and energy than meat
54
How does climate change affect food security?
Changes rainfall patterns which affects the growth of crops and reduces yields
55
How do pests and pathogens affect food security?
By causing damage to crops and livestock which reduces the amount of food therefore reducing food security
56
What happens to materials in an ecosystem?
They're constantly recycled
57
What do the living things in an ecosystem do?
Use the elements from the environment to 'make themselves' and turn them into complex compounds
58
In the carbon cycle, what is the only arrow down?
Photosynthesis
59
In the carbon cycle, what do plants use the carbon for?
To make carbs, fats and proteins
60
In the carbon cycle, how do animals get the carbon?
By eating the plants
61
In the carbon cycle, how do animals give off their carbon?
By respiring
| By dying and decomposing
62
In the carbon cycle, what happens to dead animals?
They are decomposed by microorganisms which releases carbon back into the atmosphere by respiration
63
In the carbon cycle, how does human activity contribute?
We burn: plant and animal products, fossil fuels which all release carbon through combustion
64
In the carbon cycle, what does the decomposition mean?
That habitats can be maintained as the nutrients are returned
65
Describe the role of microorganisms in the carbon cycle
Microorganisms in the carbon cycle are decomposers which break down dead organisms and waste products and release carbon through respiration as they do so
66
In the water cycle, what powers the whole thing?
The sun
67
In the water cycle, how does the water turn into water vapour?
By the sun heating the land/sea or by the sun heating plants which causes transpiration
68
What is the process of the evapouration of water from a plant called?
Transpiration
69
In the water cycle, what happens to the warm water vapour?
It gets carried upwards and cools and condenses to form clouds
70
In the water cycle, describe the steps using words
Evapouration and transpiration
Condensation
Precipitation
71
What are the methods of preventing droughts?
Thermal desalination
| Reverse osmosis
72
What does thermal desalination involve?
The heating of salt water to evapourate the water leaving the salt behind
73
Define osmosis in turns of salt concentration?
Osmosis is the net movement of water particles across a partially permeable membrane from an area of lower salt concentration to an area of higher salt concentration
74
How does reverse osmosis work?
By forcing water at extremely high pressure, into a vessel with a partially permeable membrane, which causes the water to move in the opposite direction to osmosis (up the gradient)
75
Briefly describe how to produce clean water through reverse osmosis?
Remove the salt water of solids
Send into a vessel with a partially permeable membrane at very high pressure
Collect water with the salts left behind
76
Explain how water from the sea can eventually fall as rain?
Heated by sun which causes evapouration, turning water into water vapour
Water vapour rises as hot air rises
Water vapour then cools turning into clouds
Water will then fall from the clouds as precipitation
77
Why can't nitrogen from the atmosphere be used in plants?
Because it is N2 which contains a triple covalent bond which makes it very unreactive that it can't be used directly
78
What do plants use nitrogen for?
Proteins
79
What type of nitrogen do plants use?
Nitrates
80
In the nitrogen cycle, what happens to the nitrogen the plants have used?
Gets passed along the food chains
81
In the nitrogen cycle, what happens to the nitrogen passed along the food chain?
Decomposers break down the: proteins that are found in rotting plants and animals, the urea in animal waste. Which is returned to the soil
82
What is nitrogen fixation?
The process of turning nitrogen gas into nitrogen-containing ions in the soil
83
In the nitrogen cycle, how is nitrogen fixated?
Lighting
| Nitrogen-fixing bacteria
84
In the nitrogen cycle, how does lightning contribute?
The energy of the lightning makes nitrogen react with oxygen in the air to give nitrates
85
In the nitrogen cycle, what are the four bacterias involved?
Nitrogen-fixing bacteria
Decomposers
Nitrifying bacteria
Denitrifying bacteria
86
In the nitrogen cycle, what do decomposers do?
Decompose proteins and urea and turns them into ammonia
87
What do plants do with ammonia?
Turns it into ammonium ions
88
In the nitrogen cycle, what do nitrogen-fixing bacteria do?
Turn the nitrogen gas into ammonia which forms ammonium ions
89
In the nitrogen cycle, what do nitrifying bacteria do?
Turn ammonia in decaying matter into nitrites and then into nitrates
90
In the nitrogen cycle, what do denitrifying bacteria do?
Turn nitrates back into nitrogen gas
91
Describe the benefit of denitrifying bacteria?
No benefit to living organisms
| Only benefit is that it provides the nitrogen cycle
92
In the nitrogen cycle, what is the only arrow up?
Denitrifying bacteria
93
Where are denitrifying bacteria found?
Waterlogged soils
94
Where are nitrogen-fixing bacteria found?
Soil
| Nodules on the roots of legume plants
95
Give examples of legume plants?
Peas and beans
96
Describe the relationship between legume plants and nitrogen-fixing bacteria?
Mutualistic
97
Why are legume plants and nitrogen-fixing bacteria mutualistic?
The plant supplies the bacteria with food (sugars), whilst the bacteria supplies the plant with nitrogen-containing ions which can be used to make proteins
98
Why doesn't the nitrogen cycle work with farms?
Because the crops are harvested instead of being left to die and decompose so the nitrogen they contain isn't returned to the soil
99
What does lack of nitrogen content in the soil lead to?
Poor crop growth and deficiency diseases
100
Why must farmers use methods to increase nitrate content?
Because the crops are harvested instead of being left to die and decompose which will lead to poor crop growth and deficiency diseases as there will be no nitrogen returned to the soil
101
How do farmers provide nitrogen to the soil?
Crop rotation
| Fertilisers
102
Give examples of fertilisers
Animal manure
| Compost
103
How do fertilisers increase nitrogen content?
By providing substances which have nitrates in them which adds nitrates to the soil
104
Why aren't artifical fertilisers as popular?
They are alot more expensive
105
How does crop rotation increase nitrate content?
Nitrogen-fixing crops are planted for a period of time putting nitrates back into the soil for another crop to use for a period of time
106
What does crop rotation involve?
Swapping a normal crop with a nitrogen-fixing crop every once in a while to replenish the nitrogen content of the soil
107
Give examples of nitrogen-fixing crops
Peas and beans
108
Describe how nitrogen compounds in dead leaves are turned into nitrates in the soil?
Decomposers turn the urea and protein into ammonia
| Then nitrifying bacteria turns the ammonia into nitrites which is then turned into nitrates
109
What does the number of stonefly larvae tell you?
How clean the water is
110
If you find stonefly larvae in a river what does that tell you?
The water is clean
111
What does the number of blood worms tell you?
How polluted the water is
112
If you find blood worms in a river what does that tell you?
The water is polluted
113
Give examples of organisms which indicates water is clean
Stonefly larvae
| Freshwater shrimps
114
Give examples of organisms which indicates water is polluted
Blood worms
| Sludge worms
115
What organisms can be used to monitor the concentation of sulfur dioxide
Lichen
116
What does the number of lichen tell you?
How clean the air is
117
If you find alot of lichen what does it tell you?
The air around you is very clean
118
What does the number of blackspot fungus tell you?
How clean the air is
119
If you find alot of blackspot fungus what does it tell you?
The air around you is very clean
120
Give examples of organisms which indicates the air is clean
Lichen
| Blackspot fungus
121
What are the flaws of indicator species?
No accurate figures
| Other factors causing increase or decrease in number of species
122
How can you use indicator species to measure pollution?
Count the number of species or doing a survey to see if a species is present or absent
123
What doesn't checking an area for a species absence or presence tell you?
How polluted the area is
124
What are the pros of using indicator species?
Cost-effective
| Simple
125
What are non-living indicators of pollution?
Dissolved oxygen meters and chemical tests
| Electronic meters
126
A gardener finds blackspot fungus on the leaves of her rose plant
Explain what this indicates about the local air quality
That the air is clean as the fungus is very sensitive to the level of sulfur dioxide
127
What type of organisms decompose?
Fungi and bacteria
128
What does the rate of decay depend on?
Temperature
Water content
Oxygen availability
129
Why does temperature affect rate of decay?
Because the temperature affects the rate of enzyme-controlled reactions in microbes so decay happens at different speeds depending on the temperature
130
Why does water content affect rate of decay?
Decay takes place faster in moist conditions because the organisms involved in decay need water to survive and carry out biological processes
131
Why does oxygen availability affect rate of decay?
Because most organisms involved in decay need oxygen for aerobic respiration which releases the energy needed for the decay to take place
132
How do we reduce the rate of decay?
Storing food in fridges/freezers
Storing food in airtight cans
Drying food
Adding salt/sugar
133
How does freezers/fridges reduce rate of decay?
The cold temperature slows down the decomposers' rate of reproduction or stops it altogether
134
How do airtight containers reduce rate of decay?
To stop microorganisms getting in, and if they were to get in the lack of oxygen would most likely kill them
135
How does drying the food reduce rate of decay?
By removing water that microorganisms need to survive and reproduce
136
How does adding salt to food reduce rate of decay?
By causing the water to leave via osmosis meaning the microorganisms lose water needed to survive and reproduce
137
What is compost?
Decomposed organic matter
138
When is compost produced quickest?
Warm and moist conditions with plenty of oxygen
139
Name three things that affect the rate of decay
Temperature
Oxygen availability
Water content
140
What does it mean if two species are interdependent?
They depend on each other
141
Give twp biotic factors and explain how each one could affect a community?
Competition - the stronger organisms will survive
Predation - if predators increase, prey decrease causing predators to decrease causing prey to increase (negative feedback)
142
Explain why food chains rarely have more than five trophic levels?
As you go up each trophic level there is less energy available until you get to the top bit where there is not enough energy for the predator to kill the prey
143
What is the formula for calculating the efficiency of energy transfer between trophic levels?
(Energy to next level / Energy available at previous level) x 100
144
Give four ways in which fish farms can reduce biodiversity
Waste causing eutrophication
Parasites breeding and getting out
Predators dying in the nets
Escaping of fish which become indigenous species
145
What is meant by the term food security?
The state that we have access to enough food that is safe for us to eat and has the right balance of nutrition
146
Name the process that removes carbon from the air?
Photosynthesis
147
Name two processes which put carbon back into the air
Any two from:
Combustion
Respiration
Decay
148
Name a common method of desalination
Thermal desalination
149
Describe the role of nitrogen-fixing bacteria in the nitrogen cycle
Turns nitrogen gas into ammonia which forms ammonium ions
150
Why is crop rotation beneficial to farmers?
Replenishes nitrogen content in ground, saving money which would of been spent on fertilisers whilst also providing a crop to sell
151
Explain why cold conditions can help to preserve foods
The cold conditions prevent/slow reduce the survival and reproduction of the microorganisms
152
Give three ways of increasing the rate of decomposition of compost?
By making the conditions more:
Moist
Warm
Oxygen plenty
