Brainscape's Knowledge GenomeTM

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


See full index

AQA Biology GCSE > Ecology > Flashcards

Ecology Flashcards

You may prefer our related Brainscape-certified flashcards:
GCSE Geography - AQA flashcards AP® Biology flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route A flashcards GCSE Religious Studies - Edexcel Route A flashcards GCSE Religious Studies - Eduqas Route B flashcards Biology 101 flashcards
1
Q

what does every food chain start with

A

a producer, mostly plants, sometimes algae

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

why are producers important in food chains

A

because they synthesise complex molecules
- they are the source of all biomass in a community

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

what is biomass

A

complex molecules such as glucose

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

what happens to biomass

A

it passes down the food chain to other organisms

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

what are primary consumers

A

organisms that eat producers

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

what is the secondary consumers

A

the animal that eats a primary consumer

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

what is a tertiary consumer

A

the animal that eats a secondary consumer

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

what are predators

A

consumers that kill and eat other animals

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

what are prey

A

the animal that is eaten

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

what happens if you increase the number of prey in one area

A
  • prey population increases
  • predators have more prey to kill and eat
  • more prey will be eaten and population of prey falls
  • predator have less prey to kill and eat, so population of predators fall
  • because predator population has fallen, more prey can survive and reproduce
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is random sampling used to do

A

to compare the numbers of organisms in different areas

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

how to do random sampling

A
  • using a quadrat, place it on the ground then count the number of organisms inside the quadrat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what types of organisms can random sampling be used for

A

plants or slow moving animals

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

how to carry out random sampling

A
  • quadrats placed at random locations across the area
  • one way to do this is to use random numbers to select different locations
  • count the number of each organism in the quadrat
  • keep doing this until awe have sampled a large number of random locations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why is it important that we place the quadrat a large number of times

A

to make valid results more likely. if we placed the quadrat once, it wouldnt give us a sample that represents the whole area

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

total population size equation

A

total population size = (total area/ area sampled) x number of organisms of that species counted in that sample

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

how to carry out sampling along a transect

A
  1. Place the transect so it runs across the habitat we are looking at
  2. Place the first quadrat at the start of the transect
  3. Count the different plants in the quadrat
  4. Move the quadrat closer inland by a set distance
  5. keep doing his u til you move further inland
  6. move the tape along and repeat the whole process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is a transect

A

a line such as a tape measure or a piece of rope

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

when would we use sampling along a transect

A

to see how the numbers of organisms change across a habitat

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

sampling organisms practical method

A
  1. Start by estimating the total population of daisies in a field using RANDOM SAMPLING
  2. Place two tape measures at right angles (they should be 20m in length)
  3. Get two bags filled with numbers from 1 to 20
  4. (students work in groups of 3) have one student remove a number and whatever number they get, they move to that point on the tape measure, repeat this w another students
  5. Get the third student to place the quadrat where the other students numbers meet
  6. record the number of daisies in the first quadrat
  7. Repeat this process 9 more times for a total of 10 samples
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how to improve accuracy of results

A

increase the number of quadrat throws to cover a larger percentage of an area

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

how to measure the effect of a factor on the distribution of species

A
  1. use a transect line
  2. Record the number of daises at the start of the transect and record the light intensity
  3. move the quadrat 1m down tape measure and repeat the measurements, do this all the way down the tape measure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how does the carbon cycle start

A

with co2 in the atmosphere

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

how does carbon taken into the carbon cycle

A

by photosynthesis

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

how does co2 return back to the atmosphere

A

by aerobic respiration

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

How does the carbon cycle work

A
  1. plants and algae take in co2 from the atmosphere in photosynthesis
    - plants and algae respire, so some of the co2 is released back into the atmosphere
  2. Animals eat plants, so the carbon from the plants become part if the carbs, fats and proteins in the cells of animals
    - animals respire, co2 released back to atmosphere
  3. animals release waste products such as faeces, and eventually they all die, and there is carbon in waste products and dead remains
  4. the waste products and dead remains are then broken down by decomposing microorganisms such as bacteria and fungi
  5. When decomposers carry out respiration, the carbon in the waste and dead remains returns to the atmosphere as co2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

why are decomposers important

A

they cycle materials through an ecosystem and they release mineral ions into the soil
- they release co2 back into atmosphere

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

what happens if there is a lack of oxygen for decomposers

A

they cannot function effectively, so the carbon in dead remains, can slowly be converted into fossil fuels

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

describe stages of the water cycle

A
  1. energy from the sun causes the water to evaporate from the surface of the sea
  2. The water vapour travels into the air and cools down
  3. when it cools, the water vapour condenses to form clouds
  4. the water in clouds then falls to the ground as precipitation (incl rain and snow)
  5. once the water hits the ground, some evaporates back into the atmosphere as water vapour, some of it passes through rocks and forms aquifiers, and alot of the water forms rivers or streams
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what do all forms of precipitation contain

A

fresh water

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

what is fresh water

A

water that does not contain salt

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

what role do living organisms play in the water cycle

A
  • plants take up water in their roots, the water moved up the xylem and passes out of leave’s through stomata as water vapour
  • animals take in water by food and drink, and they release water in their urine and faeces when they exhale
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what do decomposers do

A
  • return carbon back into the atmosphere
  • return mineral ions back to the soil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what are the optimum conditions for decomposers to work

A
  • decomposition takes place faster at warmer temperatures, this is because the decomposers use enzymes to break down plant material
  • moist, many of the chemical reactions in decay require water
  • good supply of oxygen so they can carry out aerobic respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

why do gardeners mix their compost regularly

A
  • to allow more oxygen to pass through the centre
  • to break large clumps
  • to increase the surface area for decomposers to act on
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what happens if decomposers dont have oxygen

A
  • decomposers carry out anaerobic decay
  • anaerobic decay produces methane, this is called biogas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

why does sour milk taste acidic

A

because bacteria use enzymes to produce acidic molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

how to investigate the effect of temperature on the decay of milk

A
  1. Label a test tube ‘lipase’ and using a pippete, place 5cm3 of lipase solution into the test tube
  2. label another test tube milk and add 5 drops of cresol red, 5cm3 of milk and 7cm3 of sodium carbonate solution into the milk test tube
    - at this point, the solution should be purple
  3. place a thermometer unto the test tube containing the milk
  4. Place both test tubes into a beaker of water at our first chosen temperature
    - start at 20 degrees
  5. wait until the temperature of the solutions is the same as the water in the beakers
  6. use a pipette to transfer 1cm3 of lipase to the test tube containing milk and stir it
    - at the same time we start a timer
    - at this point lipase will start to break down fat molecules in the milk, releasing fatty acids and causing the milk to become acidic
  7. Stop timing and record results
  8. repeat ay a range of different temperatures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

why do we use lipase in the decay practical

A

because decay is quite slow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

why shoukd the solution be purple after adding sodium carbonate

A

because sodium carbonate is alkaline and cresol red is purple in alkaline conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what happens to cresol red in acidic conditions

A

it changes from red to yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what do we do when the milk solution turns yellow

A

stop timing and record results

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what is the independent variable in decay practical

A

temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what is the dependent variable in the decay practical

A

the time taken for the milk solution to turn yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what are the control variables of the decay practical

A

the volumes of the solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

why is it important that we use a clean test tube for the milk in each experiment

A

because any traces of lipase from the previous experiment will trigger the reaction before we are ready

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

examples of environmental changes

A

seasonal, geographic, or caused by human interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

examples of environmental changes that affect distribution

A

temperature,availability of water, composition of atmospheric gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what is biodiversity

A

the variety of all the different species of organisms on earth

50
Q

why is biodiversity really important for exosystems

A

species depend on each other for food and shelter
- species help maintain the environment (eg decomposers break down remains of dead organisms)

51
Q

what does a high level of biodiversity mean

A

there are lots of different species and this will make an ecosystem more stable
- lots of different species mean that an ecosystem is less dependent on one species, so if the population of a species falls, it is less likely to affect the whole ecosystem

52
Q

how does deforestation affect biodiversity

A
  • destroys the habitats of organisms effectively killing them
53
Q

what is deforeststation

A

the cutting down of trees to provide land

54
Q

why is deforestation used

A
  • used for rice fields
  • used for grazing cattle
  • land could be used to grow crops which are then used to make biofuels
55
Q

problems with increasing human population

A
  • humans are using more of the earths resources
  • humans are producing more waste, leading to pollution
56
Q

how can waste lead to water pollution

A
  1. humans produce a large amount if sewage and this contains urine and faeces
  2. in some cases, untreated sewage us accidentally released unto rivers or streams
  3. rivers can also be polluted with fertilisers from farms
    - both of these can cause dissolved oxygen levels to fall, and this could kill aquatic organisms
57
Q

how to toxic chemicals cause pollution

A
  • they can be released into rivers from factories, killing animals in rivers
58
Q

how does waste from human activity pollute the air

A
  • burning coal in power stations can produce acidic gases, which can cause acid rain
  • combustion of fossil fuels release carbon dioxide which contribute to the greenhouse effect and leads to global warming
  • air pollution can kill plants and animals which reduces biodiversity
59
Q

how does waste contribute to land pollution

A
  • millions of tons of waste are dumped into landfills
  • landfills destroy the habitats of plants and animals
  • toxic chemicals can also leach out of landfills and pollute the soil
60
Q

what do humans use land for

A

buildings incl houses factories airports etc
- quarries
- farms
- landfills

61
Q

what do peat bogs and peat lands contain

A

large amounts of dead plant material
- large amounts of trapped carbon, since conditions mean decay is very slow

62
Q

what is peat used for

A

to produce cheap compost for gardens and farms
- burned to release energy

63
Q

what does the destruction if peat bogs lead to

A
  • reduced area of the habitat
  • reducing biodiversity
64
Q

environmental impacts of peat

A

once peat has been extracted and used for compost, it begins to decay, this releases large amounts of co2 into atmosphere
- burning peat releases co2
- these contribute to climate change

65
Q

why might some farmers not want to give up compost with pest in it

A
  • it is expensive
  • it could increase the prices of food
66
Q

human activities that increase the earths climate

A
  • burning fossil fuels
  • farming
  • rice fields
67
Q

what do greenhouse gases do

A

trap heat in the atmosphere

68
Q

what is peer review

A

when scientific research is checked by other scientists to help detect false claims and to make sure the research is valid

69
Q

effects of global warming on living organisms

A
  • loss of habitat
  • melting ice caps
  • rising sea levels
  • animals such as insects and birds may gradually extend their range north to cooler conditions
  • change in animals migration patterns
  • spring plants may flower earlier due to warmer conditions
  • we may be able to grow crops in parts of the uk
70
Q

how to reduce the negative effects of humans on biodiversity

A
  1. Breeding programmes for endangered species
  2. wetlands can be reflooded or protected
  3. Farmers can leave a strip of land around fields where wild plants and animals can live (field margins)
  4. farmers can grow hedgerows around fields for lots of species and plants to live in
  5. governments around the world trying to reduce deforestation and carbon emissions, also trying to use renewable energy
  6. recycling
71
Q

what are herbivores

A

animals that eat plants or algae

72
Q

what are carnivores

A

secondary consumers which eat herbivores

73
Q

what are tropic levels

A

positions on a food chain

74
Q

what are producers on the trophic level

A

level 1

75
Q

what are apex predators

A

a consumer that kills and eats other animals but have no predators themselves (carnivores with no predators)

76
Q

how do decomposers break down matter

A

they secrete enzymes into the environment and the enzymes digest the dead material, and the small soluble food molecules then diffuse back into the decomposer

77
Q

why is dry biomass better than wet biomass

A

the moisture content of organisms can vary widely and produce inaccurate results

78
Q

why does the amount of biomass decrease as you go up the trophic levels

A
  • because biomass is the living tissue of an organism
  • not all of the material that is eaten is absorbed, for example animals cannot break down cellulose
  • some of the biomass that is absorbed is converted into waste products of metabolism and is released
  • large amounts of biomass is used for respirations
79
Q

how to calculate the efficiency of biomass transfer

A

efficiency = gain in biomass / total biomass intake x 100

80
Q

what is food security

A

having enough food to feed a population

81
Q

why is food security important

A

more people live in cities and few people grow their own food

82
Q

what are the 6 biological threats to food security

A
  1. Birth rate increasing - as the population grows, the amount of food available will have to increase to feed the whole population
  2. Tastes changing - we now expect to eat a whole range of different foods throughout the year and many of these foods cannot be grown in the uk
  3. New pests and pathogens - they can eat food crops, pathogens cause infectious disease
  4. Environmental change - unpredictable weather can affect the growth of crops
  5. Resources - the resources farmers use to grow crops are becoming more expensive
  6. Conflicts - during period of war, farming can be disrupted and imports of food may not be possible
83
Q

approximately how much biomass is transferred every level

A

10%

84
Q

how to increase efficiency of food production (factory farming methods)

A
  • by restricting energy transfer from food to animals in the environment
  • this can be done by limiting their movement and controlling the temperature of their surroundings
  • feeding animals a higher protein diet to increase growth
85
Q

advantages of factory farming

A
  • more efficient as less biomass is wasted by the animals in respiration
  • we can also control the food that animals eat so that it contains all the nutrients they need and less food is wasted
  • in the case of chickens, eggs can be more easily harvested if the chickens are kept indoors
    • Chickens are also fed a high protein diet, they produce more eggs
  • Temperature is controlled, less biomass wasted
86
Q

disadvantages of factory farming

A
  • crowded conditions could cause infectious disease to spread more easily
  • animals in factory farms are often treated with antibiotics, this could increase the risk of antibiotic resistant bacteria
  • crowded conditions may make the animals more stressed and make them more likely to fight
  • ethical objections - people believe animals should be raised in natural conditions and be able to engage in normal behaviour
87
Q

why is it important to maintain fish stocks

A

or else certain species may disappear altogether in some areas

88
Q

what will happen if fish stocks in an area fall below a certain level

A

there are not enough mature fish to breed, commercial fishing will not be possible

89
Q

ways we can increase the number of fish

A
  1. the fishing industry set strict quotas on the numbers of fish that can be caught for each species
  2. the net size should be large enough so that smaller immature fish are not caught so that these fish can develop into adults and reproduce
90
Q

how is mycoprotein made

A

produced by a fungus fusarium
- fusarium is grown on glucose syrup in a fermenter
- in aerobic conditions, the fungus converts glucose syrup into mycoprotein
- this is harvested and purified before being made into products

91
Q

advantages of mycoprotein

A
  • suitable for vegetarians
  • we can grow very large amounts of mycoprotein in a small amount of space, making it an efficient protein source
92
Q

what is a habitat

A

the environment in which an organism lives

93
Q

what is a population

A

the total number of organisms of the same species living in the same geographical area

94
Q

what is a community

A

the populations of all of the different species that live in the same habitat

95
Q

meaning of ecosystem

A

the biotic and abiotic parts of an environment and how they interact

96
Q

what do plants compete with each other for

A

light
space
water
mineral ions in soil

97
Q

what do animals compete with each other for

A
  • food
  • water
  • mating partners
  • territory
98
Q

what is interdependence

A

all of the different species in a community depending on each other for food, shelter etc

99
Q

what is a stable community

A

one in which the populations of organisms are in balance with each other and the abiotic resources

100
Q

biotic factors

A
  • availability of food
  • arrival of a new predator
  • competition between species
  • new pathogens
101
Q

abiotic factors

A
  • light intensity
  • temperature
  • water
  • pH and mineral content of soil
  • wind intensity and direction
  • carbon dioxide and oxygen levels
102
Q

what are structural adaptations

A

adaptations of body shape or structure

103
Q

Camel adaptations

A
  • camels have a hump on their back which is a store of fat
  • fat is a thermal insulator - by storing the fat in one place, this allows heat loss from the other parts of the camels bod, reduces water loss from sweat
  • thick coat on the upper surface of their body to insulate the top of the camel from sun
  • mouth is leathery so can chew thorny plants
  • long lashes to keep sand out of eyes
104
Q

what are functional adaptations

A

adaptations to the body functions of organisms

105
Q

examples of functional adaptations

A
  • camels produce concentrated piss eww and dry faces to reduce water loss
  • camels can tolerate large changes in body temp, allows them to cope with the intense heat of the desert
106
Q

what are behavioural adaptations

A

adaptations to the animals lifestyle or behaviour

107
Q

examples of behavioural adaptations

A
  • kangaroo rats are nocturnal, this helps them avoid heat from the day time
  • during the day, they live in burrows underground, keeping them cool and protecting them from predators
108
Q

other structural adaptations

A
  • attic fox has thick fur to provide insulation and reduce heat loss to the air
  • artic fox had fur on its soles, reduces heat loss
  • small ears to reduce surface area to reduce heat loss
109
Q

Plant adaptation

A
  • waxy cuticle to reduce water loss
  • cacti have small leaves
  • cacti have extensive and shallow roots so they can catch as much water as possible after rainfall
110
Q

what are extremeophiles

A

organisms that are adapted to live in very extreme conditions

111
Q

examples of extremophiles

A

bacteria live in deep sea vents with extremely high temperatures and pressure

  • can also live in extreme concentrations of salt
112
Q

what happens if conditions become too hot for decomposers

A

enzyme will denature

113
Q

uses of biogas

A

biogas generators used to provide fuels for home

114
Q

how is methane released

A
  • produced by bacteria in paddy fields which are used to grow rice
  • released by cows when they pass wind
115
Q

what is a tertiary consumer

A

a carnivore that eats other carnivores

116
Q

What percentage of the light energy that falls on producers is absorbed and used for photosynthesis

A

1%

117
Q

how much biomass passes from one level to the other

A

10%

118
Q

disadvantage of free range chickens

A

a lot of the biomass that these chickens eat is being used in respiration, providing energy for movement
- because they’re outdoors where it can be cold, energy’s also needed to keep their body temperature constant
- less biomass available for chickens to grow and produce eggs

119
Q

why are number of fish dropping

A

trawlers use huge fishing nets to catch tons of fish at a time

120
Q

what is vitamin a needed for

A

effective vision

AQA Biology GCSE (36 decks)

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