Biology - ecology Flashcards
1
Q
How to use a quadrat to study the distribution of small organisms
A
Place a 1m squared quadrat on the ground at a random point within the first sample area. Usually find the point by using 2 rules at right angles from each other and using the random function on the calculator to provide coordinates.
Count all organisms within the quadrat
Repeat steps as many times as you can
Work out the mean number of organisms per quadrat within the first sample area
Repeat all steps in the second sample area
Compare the two means
2
Q
Habitat
A
A place where an organism lives
3
Q
Population
A
All the organisms of one species living in a habitat
4
Q
Community
A
The populations of different species living in a habitat
5
Q
Abiotic factors
A
non living factors of the environment, eg. temperature
6
Q
Biotic factors
A
living factors of thew environment, eg. food
7
Q
Ecosystem
A
The interaction of a community of living organisms with the nonliving parts of the environment
8
Q
What resources do plants compete for
A
light
space
water
mineral ions
9
Q
What resources do animals compete for
A
space (territory)
food
water
mates
10
Q
Interdependence
A
In a community each species depends on other species for things like food, shelter, pollination and seed dispersal
11
Q
What does the interdependence of all living things in an ecosystem mean
A
Means that any major change in the ecosystem can have far reaching affects
12
Q
Stable communities
A
All the species and environmental factors are balanced so that he population sizes are roughly constant
13
Q
Examples of stable communities
A
- tropical rainforest
- ancient oak woodlands
14
Q
Examples of abiotic factors
A
- moisture levels
- light intensity
- temperature
- carbon dioxide levels (for plants)
- wind intensity
- oxygen levels
- soil pH and mineral content
15
Q
How could a decrease light affect population size
A
A decrease in light intensity could decrease the rate of photosynthesis in a plant species. This could cause an affect on plant growth and cause a decrease in the population size.
16
Q
How could a decrease in the mineral content of soil cause a decrease in population size
A
Decrease in mineral content of soil could lead to nutrient deficiencies. This could also affect plant growth and cause a decrease in the population size.
17
Q
Examples of biotic factors
A
- new predators
- competition
- new pathogens
- availability of food
18
Q
Adaptations
A
The features or characteristics that allows an organism to live in different environmental conditions.
19
Q
Types of adaptations
A
- structural
- behavioural
- functional
20
Q
Example of structural adaptations
A
- colour to help camouflage
- layers of fat to keep warm
- size of surface area to volume ratio
21
Q
Example of behavioural adaptation
A
Many species migrate to warmer climates during the winter to avoid the problems of living in cold conditions
22
Q
Functional adaptations
A
Things that go on inside an organism’s body that can be related to processes like reproduction and metabolism
23
Q
Example of functional adaptation
A
Desert animals conserve water by providing very little sweat and small amounts of concentrated urine
24
Q
What do food chains start with
A
Start with the producer
25
Producers
Make their own food using energy from the sun - usually green plants or algae
26
Biomass
The mass of living material - energy stored in plaNts
27
Organisms in the food chain
Producers
Primary consumers
Secondary consumers
Tertiary consumers
28
Predators
Consumers that hunt and kill other animals
29
What is the population of a species limited by
The amount of food available. If the population of prey increase then so will the predators, however as the population of predators increase then the prey will decrease
30
Distribution of an organism
Where an organism is found
31
How to use transects to study the distribution of organisms along a line
Marl out a line in the area you want to study using a tape meausure
Collect data along the line by just counting all the organisms you're interested in that touched the line
Collect data by using quadrats
32
What does a change in distribution mean
Means a change in where an organism lives
33
Environmental changes that can affect the distribution of an organism
- change in the availability of water
- change in temperature
- change in the composition of atmosphere
34
Describe the water cycle
Energy from the sun makes the water evaporate from the land and sea, turning it into water vapour. Water also evaporates from plants (transpiration)
The warm water vapour is carried upwards as warm air rises. When it gets higher up it cools and condenses to form clouds.
Water falls from clouds as precipitation onto land, where it provides fresh water for plants and animals
It then drains into the sea before the whole process starts again
35
What causes elements to be cycled back to the start of the food chain
Decay
36
What do plants turn carbon, oxygen, hydrogen and nitrogen into
Turn elements from the sol and the air into complex compounds (carbohydrates, proteins and fats) that make up living organisms. These get passed up the food chain
37
How are the complex compounds returned back to the environemnt
In waste products or when the organism dies and decays. Decay puts the stuff that plants need to grow, back into the soil.
38
Why do materials decay
Because they are broken down (digested) by microorganisms.
39
Conditions where decay is faster
Decay is faster in warm, moist, aerobic (oxygen rich) conditions because microorganisms are more active in these conditions
40
How is co2 removed from the atmosphere
By green plants and algae during photosynthesis. the carbon is used to make glucose which can be turned into fats, carbohydrates and proteins that make up the body of the plants and algae.
41
How do plants and algae release co2 in to the atmosphere
- plant respiration
- when plants, animals and algae die, other animals and microorganisms feed on their remains. When these organisms respire co2 is returned into the atmosphere
-
42
How do animals release co2 into the atmosphere
- animal respiration
- death and waste which is broken down my microogranisms
43
How does human activity release co2 into the air
- the combustion of wood and fossil fuels releases co2
44
What can decomposition produce
compost
45
What is compost
Decomposed organic matter that is used as a natural fertiliser for crops and garden plants
46
What organisms are responsible for decomposition
- microorganisms like bacteria and fungi
- detritus feeders
47
How do higher temperatures make things decompose quicker
They increase the rate that the enzymes involved in decomposition work at. If it's too hot though then decomposition slows down as the enzymes are destroyed and the organisms die. Really slow temps slow the rate of decomposition too.
48
How does oxygen availability make things decompose quicker
Many organisms need oxygen to respire, which they need to do to survive. The microorganisms involved in anaerobic decay don't need oxygen though.
49
How does water availability make things decompose quicker
Decay takes place faster in moist environments because the organisms involved in decay need water to carry out biological process.
50
How is biogas made
Through the anaerobic decay of waste materials. This type of decay produces methane gas
51
What is biogas made up of
Methane which can be burned as a fuel
52
What is used to make biogas on a large scale
Sludge waste
53
Where is biogas made
In a simple fermenter called a digester or generator.
54
Condition of biogas generators
Need to be kept at a constant temperature to keep microorganisms respiring away
55
What is biogas used for
Cant be stored as a liquid so it has to be used straight away - for heating, cooking lighting or to power a turbine to generate elctricity
56
Two main types of biogas generators
- batch generators
- continuous generators
57
Batch generators
Makes biogas in small batches
Manually loaded up with waste which is left to digest and the by-products are cleared away after every session
58
Continuous generators
Make biogas all the time
Waste is continuously fed in and biogas is produced at a steady rate
Continuous generators are more suited to large scale biogas projects
59
Things that biogas generators must have
An inlet for waste material to put in
An outlet for the digested material be removed through
An outlet so that the biogas can be piped to where it is needed
60
Decay practical
Measure out 5cm cubed of lipase solution and add it to a test tube. Label this tube with a. letter L for lipase
Measure out 5cm cubed of milk and add it to a different test tube
Add 5 drops of phenolphthalein indicator to the test tube containing milk
Then measure out 7cm cubed of sodium carbonate solution and add it to the milk and indicator test tube. This makes the solution in the tube alkaline so it should turn pink.
Put both tubes into a water bath set to 30 degrees and leave them to reach the temp of the water bath, use thermometer to check this
Once the tubes have reached 30 degrees use a calibrated dropping pipette to put 1 cm cubed of the lipase solution into the milk tube and start a stopwatch straight away.
Stir the contents of the tube with a glass rod, the enzyme will start to decompose the milk
As soon as the solution loses its pink colour stop the stop watch and record how long the colour change took in a table
Repeat the experiment at a range of different temps
Carry experiment out three times at each temp and calculate meantime
use results to calculate rate of decay
61
Biodiversity
The variety of different species of organisms on Earth, or within am ecosystem
62
Why is high biodiversity important
Helps to make ecosystems more stable because different species depend on each other for things like food and shelter
63
How can we reduce the negative effects of humans on biodiversity
- Use breeding programmes for endangered species
- protecting and regenerating wetlands so they can never be drained
- Field margins create a place where wild animals can live
- hedge rows help to preserve biodiversity in farms
- Government action - renewable energy
- individuals - recycling waste materials so less waste ends up in landfills so fewer habitats are destroyed
64
how does increased population affect the environment
- puts pressure on the environment as we take the resources we need to survive
- use more raw materials and energy for manufacturing processes
- raw materials are being used up quicker than they're replaced so if we carry on like we are, one day we are going to run out
65
How do waste products from human activity affect the environment
Unless the waste is properly handled harmful pollution will be caused. Pollution affects water, land and air and kills plants and animals, reducing biodiversity.
66
How does waste in water affect biodiversity
Sewage and toxic chemicals from industry can pollute lakes, rivers and oceans, affecting the plants and animals that rely on them for survival. Chemicals used on land can be washed into water
67
How does waste on land affect biodiversity
We use toxic chemicals for farming. We also bury nuclear waste underground and we dump a lot of household waste into landfill sites
68
How does waste chemicals in air affect biodiversity
Smoke and acidic gases released into the atmosphere can pollute the air e.g. sulfur dioxide can cause acid rain
69
What role do carbon dioxide and methane play in global waring
Trap energy from the sun. Gases In the atmosphere act as an insulating layer. They absorb most of the energy that would normally be radiated out into space, and re-radiate it in all directions. This increases the earths temperature.
70
How is the temperature of the earth a balance
Its a balance between the energy it gets from the Sun and the energy it radiates back out into space
71
Global warming
The Earth is gradually heating up due to an increase in greenhouse gases
72
4 consequences of global warming
- flooding
- distribution of species
- changes in migration patterns
- reduction of biodiversity
73
How can flooding be a result of global warming
Higher temp causes seawaters to expand and ice to melt, causing the sea levels to rise
74
How is the distribution of species be a result of global warming
The distribution many wild animals and plants may change as temp increases and amount of rainfall changes in different areas.
75
How is reduction of biodiversity a result of global warming
If some species are unable to survive a change in the climate and become extict
76
What traps co2
Trees and peat bogs
77
Problems with deforestation
- less co2 is taken in - the amount of co2 removed from the atmosphere during photosynthesis is reduced.
- trees lock up some of their carbon that they absorb during photosynthesis, removing trees means less is locked up
- co2 is released when trees are burnt to clear land
- microorganisms feeding on bits of dead wood releases co2 as a waste product of respiration
- less biodiversity habitats like forest contain a huge number of different species of plants and animals, so when they are destroyed their is a danger of many species becoming extinct
78
How do bogs create peat
They are acidic and waterlogged meaning the plants that live in the bogs don't fully decay when they die because theirs not enough oxygen. The partly-rotted plants gradually build up to form peat
79
How do peat bogs trap co2
The carbon in the plant is stored in the peat instead of being released into the atmosphere
80
Why are peats drained
So the area can be used for farmland or the peat is cut up and dried to use as fuel. Sold to gardeners as compost.
81
How does destroying peatbogs release co2
When peat is drained it comes into contact with air and then some microorganisms decompose it. When these microorganisms respire they release co2.
Co2 is also released when peat is burned as a fuel
Destroying the bogs also destroys the habitats of some of the animals, plants and microorganisms that live there so reduces biodiversity
82
Conflicting pressures that affects how biodiversity is maintained
Costs money
Could affect peoples lively hooFood security also needs to be protected
83
