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B7 ECOLOGYPractice questions
Name: ________________________
Class: ________________________
Date: ________________________
Time: 153 minutes
Marks: 151 marks
Comments: FOUNDATION TIER
Page 1 of 61
Moose are animals that eat grass.
Figure 1 shows a moose.
Figure 1
© Wildnerdpix/iStock/Thinkstock
Figure 2 shows a food chain.
Figure 2
Grass Moose Wolves
(a) What word describes the grass in Figure 2?
Tick one box.
Consumer
Predator
Prey
Producer
(1)
1
Page 2 of 61
(b) What word describes the wolves in Figure 2?
Tick one box.
Communities
Predators
Prey
Producers
(1)
Page 3 of 61
(c) Figure 3 and Figure 4 show how the moose population and the wolf population changed inone area.
Figure 3
Figure 4
Look at Figure 3.
In this area the moose population reached its peak in 2002.
What was the size of the moose population in 2002?
___________________________________________________________________
(1)
Page 4 of 61
(d) Look at Figure 4.
How long after the moose population peak did the wolf population peak occur?
___________________ years
(1)
(e) When the moose population increases, the wolf population increases soon after.
Why does the wolf population increase?
Tick one box.
There is more competition for moose
There is more food for wolves
Other animals prey on moose
There are more predators of wolves
(1)
(f) Abiotic factors and biotic factors can affect the size of the wolf population.
Which of these are biotic factors?
Tick two boxes.
Carbon dioxide levels
Humans hunting
Light intensity
Soil type
Viruses
(2)
(Total 7 marks)
Page 5 of 61
Global warming may reduce biodiversity in some areas.
(a) What is biodiversity?
Tick one box.
The different habitats in an ecosystem
The interaction of living and non-living factors in a habitat
The interdependence of organisms on Earth
The total number of organisms in an ecosystem
The variety of different species on Earth
(1)
2
(b) What gases cause global warming?
Tick two boxes.
Carbon dioxide
Methane
Nitrogen
Oxygen
Water vapour
(2)
Page 6 of 61
(c) Give two effects of global warming that could reduce biodiversity in an area.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________
(2)
(Total 5 marks)
Page 7 of 61
Peat can be burnt as a fuel.
Table 1 shows the amount of peat used as a fuel in the UK over 20 years.
Table 1
YearMass of peat used as a
fuel in units
1990 110
1995 80
2000 50
2005 20
2010 10
Figure 1 shows some of the information from Table 1.
Figure 1
3
Page 8 of 61
(a) Complete Figure 1 by plotting the points for 2005 and 2010.
(2)
(b) Predict the amount of peat used as a fuel in the UK in 2015.
Use information from Figure 1.
___________________________________________________________________
(1)
(c) Plants in the UK are often grown in compost.
Compost usually contains peat.
The coconut fibre shown in Figure 2 is a waste product of coconut farming.
Coconut fibre can be used to produce peat-free compost.
Figure 2
© afe207/Thinkstock
Table 2 shows features of peat-free compost made using coconut fibre.
Complete Table 2 to show if each feature is an advantage or disadvantage.
Put a tick in each row.
Table 2
Feature compared to peat compost Advantage Disadvantage
Coconut fibre is transported longer distances
Coconut fibre is a waste product
Coconut fibre traps less air in the soil, so rootsabsorb fewer mineral ions
(2)
(Total 5 marks)
Page 9 of 61
Feeding relationships can be shown using food chains.
The figure below shows a food chain for organisms in a habitat.
(a) What is the producer in the food chain?
Tick one box.
Beetle
Leaf
Mouse
Owl
(1)
4
(b) Name the primary consumer in the food chain.
___________________________________________________________________
(1)
Page 10 of 61
(c) What is the group of leaves, beetles, mice and owls in a habitat called?
Tick one box.
Community
Ecosystem
Population
Species
(1)
(d) What are two abiotic factors that can affect the food chain?
Tick two boxes.
Availability of food
Light intensity
New diseases
New predators
Wind direction
(2)
(Total 5 marks)
Page 11 of 61
The figure below shows the carbon cycle.
Use the information from the figure above to answer the questions.
(a) In process A, carbon dioxide in the atmosphere is taken into plants.
What is process A?
Tick one box.
Evaporation
Fossilisation
Photosynthesis
Respiration
(1)
5
Page 12 of 61
(b) In process B, carbon dioxide is released from plants and animals into the atmosphere.
What is process B?
Tick one box.
Burning
Feeding
Photosynthesis
Respiration
(1)
(c) In which process is carbon passed from one organism to another?
Tick one box.
A
B
C
D
(1)
(d) What will happen to the concentration of carbon dioxide in the atmosphere if lots of treesare cut down?
___________________________________________________________________
___________________________________________________________________
(1)
Page 13 of 61
(e) Greenhouse gases cause global warming.
Carbon dioxide is a greenhouse gas.
Name two other greenhouse gases.
1. _________________________________________________________________
2. _________________________________________________________________
(2)
(f) When living organisms die the dead material decays and is broken down.
The process of decay returns carbon dioxide to the atmosphere.
What type of organism causes decay?
___________________________________________________________________
(1)
(Total 7 marks)
Page 14 of 61
A student investigated the number of ribwort plants in a field.
The student used the apparatus shown in Figure 1.
Figure 1
This is the method used.
1. Place the quadrat in an area where there are lots of ribwort plants in the field.
2. Count the number of ribwort plants inside a quadrat.
3. Repeat steps 1 and 2 four more times.
(a) How could the student improve his method so that he can collect valid results?
Tick two boxes.
Count the leaves of each ribwort plant
Place more quadrats in the field
Place the quadrats randomly
Use a smaller quadrat
Weigh the ribwort plants
(2)
6
Page 15 of 61
(b) The student calculated that the mean number of ribwort plants per m2 was 3.2
The area of the field was 8250 m2.
Calculate the total number of ribwort plants in the field.
___________________________________________________________________
Total number of ribwort plants = ________________
(1)
(c) Another group of students did an investigation in the field.
Figure 2 shows how the students placed their quadrats in this investigation.
Figure 2
What is the name given to the line in Figure 2?
___________________________________________________________________
(1)
Page 16 of 61
(d) Figure 3 shows the students’ results.
Figure 3
Describe the relationship shown in Figure 3.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
Page 17 of 61
(e) What is one reason why there are no ribwort plants next to the path?
Tick one box.
There is less light near the path
The ribwort plants get walked on
There are more nutrients in the soil near the path
There are fewer animals near the path
(1)
(Total 7 marks)
(a) Which term describes organisms that can tolerate very hot or very cold places?
Draw a ring around the correct answer.
an environmentalspecies
an extremophilespecies
an indicatorspecies
(1)
7
Page 18 of 61
(b) Figure 1 shows photographs of an Adelie penguin and a chinstrap penguin. Adeliepenguins and chinstrap penguins live in the Antarctic at temperatures below 0 °C.
Adelie penguins spend most of their time on the ice around the Antarctic.Chinstrap penguins live mainly in the sea around the ice.Since 1965 the number of Adelie penguins has decreased by 6 million.
Figure 2 shows changes to the ice around the Antarctic over the past 50 years.
(i) Use information from Figure 2 to explain why the number of Adelie penguins hasdecreased since 1965.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
Page 19 of 61
______________________________________________________________
(2)
(ii) Suggest what has happened to the number of chinstrap penguins since 1965.
Draw a ring around your answer. increase / decrease
Give a reason for your answer.
______________________________________________________________
______________________________________________________________
(1)
(c) The number of penguins can be used to monitor changes in temperature of theenvironment.
Temperature readings could also be taken using a thermometer.
What is the advantage of using penguins, instead of a thermometer, to monitor changes intemperature of the environment?
Tick ( ) one box.
Living organisms show long-term changes.
Thermometers cannot measure temperatures below 0 °C.
Thermometers do not give accurate readings.
(1)
(Total 5 marks)
Page 20 of 61
Some students investigated the distribution of dandelion plants in a grassy field. The grassy fieldwas between two areas of woodland.
Figure 1 shows two students recording how many dandelion plants there are in a 1 metre x 1metre quadrat.
Figure 1
© Science Photo Library
8
Figure 2 shows a section across the area studied and Figure 3 shows a bar chart of thestudents’ results.
Figure 2
Distance in m
Figure 3
Distance in m
Page 21 of 61
(a) How did the students use the quadrat and the 30-metre tape measure to get the results inFigure 3?
Use information from Figure 1.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
(b) (i) Suggest one reason why the students found no dandelion plants under the trees.
______________________________________________________________
______________________________________________________________
(1)
(ii) Suggest one reason why the students found no dandelion plants at 16 metres.
______________________________________________________________
______________________________________________________________
(1)
(c) The teacher suggested that it was not possible to make a valid conclusion from theseresults.
Describe how the students could improve the investigation so that they could make a validconclusion.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 7 marks)
Page 22 of 61
The picture shows a basilisk lizard. Some of the adaptations of the lizard are labelled.
Basilisk lizards are often found resting on branches of trees that grow next to water.Basilisk lizards can run across the surface of the water.
(a) Draw one line from each adaptation of the lizard to the advantage of the adaptation.
Adaptation Advantage
For camouflage onbranches of trees
Toes on the backfeet are webbed
Helps the lizard tobalance when running
Long tail
Warning colours todeter predators
Brown skin
Increases surfacearea in contact with
the water
(3)
9
(b) Suggest one advantage to the basilisk lizard of being able to run across the surface of thewater.
___________________________________________________________________
___________________________________________________________________
(1)
Page 23 of 61
(c) Animals, such as lizards, compete with each other.
Give two factors that animals compete for.
Tick ( ) two boxes.
Oxygen
Food
Territory
Light
(2)
(Total 6 marks)
Some students wanted to find the number of thistle plants growing on a lawn.The students placed 10 quadrats at different positions on the lawn.Each quadrat measured 1 metre × 1 metre.The students counted the number of thistle plants in each quadrat.
(a) Which method should the students use to decide where to place the 10 quadrats?
Tick ( ) one box.
Place the quadrats as evenly as possible around the lawn.
Place 5 quadrats in areas with many thistle plants and 5 quadrats in areaswith only a few thistle plants.
Place all the quadrats randomly on the lawn.
(1)
10
Page 24 of 61
(b) The diagram shows the lawn with the positions of the thistle plants and the students’ 10quadrats.
(i) Complete the table to show:
• how many thistle plants the students found in each of the first four quadrats
• the total number of thistle plants found in all 10 quadrats.
Quadratnumber
Number of thistleplants in each
quadrat 1
2
3
4
5 1
6 3
7 0
8 0
9 2
10 1
Total
(2)
Page 25 of 61
(ii) Calculate the mean number of thistle plants in one quadrat.
______________________________________________________________
Mean = ______________________________________________
(1)
(iii) The lawn measured 12 metres long and 10 metres wide.
Use your answer from part (b)(ii) to estimate the number of thistle plants on the lawn.
______________________________________________________________
______________________________________________________________
Estimated number of thistle plants = _______________________
(2)
(c) How could the students make their estimate more accurate?
___________________________________________________________________
___________________________________________________________________
(1)
(Total 7 marks)
Students used quadrats to estimate the population of dandelion plants on a field.
(a) Describe how quadrats should be used to estimate the number of dandelion plants in afield.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(4)
11
Page 26 of 61
(b) The field measured 40 m by 145 m.
The students used 0.25 m2 quadrats.
The students found a mean of 0.42 dandelions per quadrat.
Estimate the population of dandelions on the field.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Estimated population of dandelions = ______________
(2)
(c) In one area of the field there is a lot of grass growing in the same area as dandelions.
Suggest why the dandelions may not grow well in this area.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(4)
(Total 10 marks)
Page 27 of 61
Moose are animals that eat grass.
Figure 1 shows a moose.
Figure 1
© Wildnerdpix/iStock/Thinkstock
Figure 2 shows a food chain.
Figure 2
Grass Moose Wolves
(a) Name the secondary consumer shown in Figure 2.
___________________________________________________________________
(1)
12
Page 28 of 61
(b) Figure 3 shows how the moose population and wolf population have changed in one area.
This is a predator-prey cycle.
Figure 3
In 2004 the line on Figure 3 for wolves is above the line for moose.
How does Figure 3 show that there are more moose than wolves in 2004?
___________________________________________________________________
___________________________________________________________________
(1)
(c) Suggest why the moose population decreased between 2002 and 2004.
Use information from Figure 3.
___________________________________________________________________
___________________________________________________________________
(1)
(d) The number of wolves is one biotic factor that could affect the size of the moosepopulation.
Give two other biotic factors that could affect the size of the moose population.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________
(2)
Page 29 of 61
(e) Moose have distinct characteristics such as antlers.
Describe how moose may have evolved to have large antlers.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(5)
(Total 10 marks)
A grassy field on a farm measured 120 metres by 80 metres.
A student wanted to estimate the number of buttercup plants growing in the field.
The student found an area where buttercup plants were growing and placed a 1 m × 1 m quadratin one position in that area.
Figure 1 shows the buttercup plants in the quadrat.
13
Page 30 of 61
The student said, 'This result shows that there are 115 200 buttercup plants in the field.'
(a) (i) How did the student calculate that there were 115 200 buttercup plants in the field?
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(ii) The student’s estimate of the number of buttercup plants in the field is probablynot accurate. This is because the buttercup plants are not distributed evenly.
How would you improve the student’s method to give a more accurate estimate?
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(b) Sunlight is one environmental factor that might affect the distribution of the buttercupplants.
(i) Give three other environmental factors that might affect the distribution of thebuttercup plants.
1. ____________________________________________________________
2. ____________________________________________________________
3. ____________________________________________________________
(3)
(ii) Explain how the amount of sunlight could affect the distribution of the buttercupplants.
(3)
Page 31 of 61
(c) Figure 2 is a map showing the position of the farm and a river which flows through it.
Every year, the farmer puts fertiliser containing mineral ions on some of his fields.Whenthere is a lot of rain, some of the fertiliser is washed into the river.
(i) When fertiliser goes into the river, the concentration of oxygen dissolved in thewater decreases.
Explain why the concentration of oxygen decreases.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(5)
(ii) There is a city 4 km downstream from the farm.
Apart from fertiliser, give one other form of pollution that might go into the river as itflows through the city.
______________________________________________________________
Page 32 of 61
(1)
(d) Three sites, A, B and C, are shown in Figure 2.
Scientists took many samples of river water from these sites.
The scientists found larvae of three types of insect in the water: mayfly, stonefly andcaddisfly. For each type of insect the scientists found several different species.
The scientists counted the number of different species of the larvae of each of the threetypes of insect.
Figure 3 shows the scientists’ results.
(i) How many more species of mayfly were there at Site B than at Site A?
____________________
(1)
(ii) Suggest what caused this increase in the number of species of mayfly.
______________________________________________________________
______________________________________________________________
(1)
(iii) The scientists stated that the number of species of stonefly was the bestindicator of the amount of oxygen dissolved in the water.
Use information from Figure 3 to suggest why.
(1)
(Total 19 marks)
Page 33 of 61
This question is about carbon.
The graph shows the mass of carbon added to and removed from the atmosphere each year.
(a) Name process X.
___________________________________________________________________
(1)
14
(b) (i) Calculate the mass of carbon added to the atmosphere by respiration per year.
Answer = ____________________ billion tonnes
(1)
(ii) Some scientists are concerned that the mass of carbon in the atmosphere ischanging.
How does the data in the graph support this idea?
______________________________________________________________
______________________________________________________________
(1)
(Total 3 marks)
Page 34 of 61
Organisms compete with each other.
(a) Figure 1 shows two types of seaweed which live in similar seashore habitats.
Most of the time the two seaweeds are covered with water.
Bladder wrack has bladders filled with air.
Bladder wrack grows more quickly than saw wrack.Suggest an explanation why.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
15
Page 35 of 61
(b) Figure 2 shows an angler fish.
© Dante Fenolio/Science Photo Library
Angler fish live at depths of over 1000 m.
In clear water, sunlight does not usually reach more than 100 m deep.Many angler fish have a transparent ‘lure’ containing a high concentration ofbioluminescent bacteria.Bioluminescent bacteria produce light.
Suggest an advantage to the angler fish of having a lure containing bioluminescentbacteria.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 5 marks)
Page 36 of 61
Human activities have many effects on our ecosystem.
The graph shows the volume of peat compost and peat-free compost used in gardening from1999 to 2009.
(a) Describe the trends shown in the graph.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
16
(b) What effect does the destruction of peat bogs have on the gases in the atmosphere?
___________________________________________________________________
___________________________________________________________________
(1)
(c) Deforestation is also damaging ecosystems.
Describe one effect of deforestation on ecosystems.
(1)
(Total 4 marks)
Page 37 of 61
The photograph shows a fossil of a prehistoric bird called Archaeopteryx.
By Ghedoghedo (own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/BY-SA-3.0) or GFDL (http://www.gnu.org/copyleft
/fdl.html)], via Wikimedia Commons; By Steenbergs from Ripon, United Kingdom (Small Fishing Boat In North Sea) [CC-BY-2.0
(http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons.
17
(a) Describe three ways fossils can be made.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
Page 38 of 61
(b) The drawing shows what an Archaeopteryx might have looked like when it was alive.
Scientists think that Archaeopteryx was a predator.
(i) Look at the drawing.
Write down three adaptations that might have helped Archaeopteryx to catch prey.
How would each adaptation have helped Archaeopteryx to catch prey?
Adaptation 1 ___________________________________________________
How it helps ____________________________________________________
______________________________________________________________
Adaptation 2 ___________________________________________________
How it helps ____________________________________________________
______________________________________________________________
Adaptation 3 ___________________________________________________
How it helps ____________________________________________________
______________________________________________________________
(3)
Page 39 of 61
(ii) Archaeopteryx is now extinct.
Give two reasons why animals may become extinct.
1. ____________________________________________________________
______________________________________________________________
2. ____________________________________________________________
______________________________________________________________
(2)
(Total 8 marks)
Freshwater streams may have different levels of pollution. The level of pollution affects whichspecies of invertebrate will live in the water.
Table 1 shows the biomass of different invertebrate species found in two different streams, X andY.
Table 1
Biomass in g
Invertebrate species Stream X Stream Y
Mayfly nymph 4 0
Caddis fly larva 30 0
Freshwater shrimp 70 5
Water louse 34 10
Bloodworm 10 45
Sludge worm 2 90
Total 150 150
18
(a) The bar chart below shows the biomass of invertebrate species found in Stream X.
(i) Complete the bar chart by drawing the bars for water louse, bloodworm and sludgeworm in Stream Y.
Use the data in Table 1.
Page 40 of 61
Species present
(2)
(ii) Table 2 shows which invertebrates can live in different levels of water pollution.
Table 2
Pollution level Invertebrate species likely to be present
Clean water Mayfly nymph
Low pollution Caddis fly larva, Freshwater shrimp
Medium pollution Water louse, Bloodworm
High pollution Sludge worm
Which stream, X or Y, is more polluted?Use the information from Table 1 and Table 2 to justify your answer.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
Page 41 of 61
(b) There is a sewage works near another stream, Z.
An accident caused sewage to overflow into Stream Z.Two weeks later scientists took samples of water and invertebrates from the stream.They took samples at different distances downstream from where the sewage overflowed.The scientists plotted the results shown in Graphs P and Q.
Graph P: change in water quality downstream of sewage overflow
Graph Q: change in invertebrates found downstream of sewage overflow
Page 42 of 61
(i) Describe the patterns shown in Graph P.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(4)
(ii) Describe the relationship between dissolved oxygen and the survival of mayflynymphs in Stream Z. Suggest a reason for the pattern you have described.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(3)
(c) Many microorganisms are present in the sewage overflow.
Explain why microorganisms cause the level of oxygen in the water to decrease.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(Total 13 marks)
Page 43 of 61
The diagram below shows a single-celled alga which lives in fresh water.
19
(a) Which part of the cell labelled above:
(i) traps light for photosynthesis
______________________________________________________________
(1)
(ii) is made of cellulose?
______________________________________________________________
(1)
(b) In the freshwater environment water enters the algal cell.
(i) What is the name of the process by which water moves into cells?
______________________________________________________________
(1)
(ii) Give the reason why the algal cell does not burst.
______________________________________________________________
______________________________________________________________
(1)
(c) (i) The alga can photosynthesise.
Complete the word equation for photosynthesis.
water + _______________ _______________ + oxygen
(2)
Page 44 of 61
(ii) The flagellum helps the cell to move through water. Scientists think that the flagellumand the light-sensitive spot work together to increase photosynthesis.
Suggest how this might happen.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(d) Multicellular organisms often have complex structures, such as lungs, for gas exchange.
Explain why single-celled organisms, like algae, do not need complex structures for gasexchange.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
(Total 11 marks)
A project called Garden Bird Watch counts the UK populations of common birds. 16 000 peoplecount the number of birds in their gardens every week of the year.
The results are analysed by researchers and written up in important scientific magazines.
20
Page 45 of 61
(a) Suggest one advantage of this method of collecting data.
___________________________________________________________________
___________________________________________________________________
The table below shows the percentage (%) of gardens visited by different bird species in1995 and in 2011.
Bird species% of gardensvisited in 1995
% of gardensvisited in 2011
Goldfinch 12 58
Greenfinch 71 54
House sparrow 84 64
Starling 71 42
Woodpigeon 48 80
(1)
(b) (i) Complete the bar chart below, by plotting the data from the table above for 2011.
Some have been done for you.
Bird species
(2)
Page 46 of 61
(ii) In this survey, the results from 16 000 gardens were sent in.
How many gardens were visited by woodpigeons in 2011?
______________________________________________________________
(2)
(iii) Which bird species has increased the most from 1995 to 2011?
______________________________________________________________
(1)
(c) The change in the number of woodpigeons may be partly because they have spread totowns and cities.Suggest why this increase in woodpigeons in towns and cities might have occurred.
___________________________________________________________________
___________________________________________________________________
(1)
(Total 7 marks)
Page 47 of 61
Mark schemes
(a) producer11
(b) predators1
(c) 12001
(d) 2 (years)1
(e) there is more food for wolves1
(f) humans hunting1
viruses1
[7]
(a) the variety of different species on Earth12
(b) carbon dioxide1
methane1
(c) any two from:
• drought• flooding• temperature change
allow temperature increase or decrease• rainfall change
allow rainfall increase or decrease2
[5]
(a) both plots correct13
suitable line of best fit1
(b) allow range of 3−7 (units)allow ecf from line of best fit given in 03.1
1
Page 48 of 61
(c)
Advantage Disadvantage
✔✔✔✔
✔✔✔✔
✔✔✔✔
allow 1 mark for 2 correct2
more than one tick in a row negates a mark
[5]
(a) Leaf14
(b) Beetle1
(c) Community1
(d) Light intensity1
Wind direction1
[5]
(a) Photosynthesis15
(b) Respiration1
(c) C1
(d) (it will) rise1
(e) water vapour1
methane1
(f) Microorganism1
[7]
(a) Place more quadrats in the field16
Page 49 of 61
Place quadrats randomly1
(b) 26 4001
(c) transect1
(d) as distance from the path increases the number of (ribwort) plants increases1
steep rise from 0.5 to 3.0 between 2 and 4 m from path or numbers level off to about 4plants from 10 m from the path
1
(e) The ribwort plants get walked on1
[7]
(a) an extremophile species17
(b) (i) smaller ice area
allow smaller amount of ice
allow less ice1
(so) less habitat
allow fewer places to live / nest1
(ii) either increaseas more sea to live inoras less competition for food
or decreaseas less space (ice) to lay eggsorpredators more likely to eat them
there is no mark for increase / decrease alone. The mark is for anappropriate reason linked to increase / decrease
if increase / decrease not ringed the mark may be awarded if it isclear in the explanation which is intended
1
(c) Living organisms show long-term changes.1
[5]
Page 50 of 61
(a) any three from:
• place 30-m tape measure across field / from one wood to the other• place quadrat(s) next to the tape• count / record the number / amount of dandelions / plants in the quadrat
ignore ‘record the results’
ignore measures / estimates dandelions• repeat every 2 metres
allow every metre / at regular intervals3
8
(b) (i) low light / it is shady
allow no light
ignore sun / rays
ornot enough water / ions / nutrients
accept correct named ion
ignore no water / ions / nutrients
orwrong pH of soil
accept competition with trees for light / water / ions
ignore competition for space and competition unqualified
accept soil too acidic / too alkaline
ignore temperature1
(ii) sensible suggestion for a small area, eg chance variation / anomaly / poisonedby animal waste / wrong pH of soil / eaten (by animals) / cut down / footpath
1
(c) repeat (transect) / compare with the results of other groups
allow ‘do it in two different locations’ for 2 marks1
at different / random location(s) / elsewhere (across the field)
do not allow ‘in other fields’1
[7]
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(a)
one mark for each line
do not award mark for an adaptation if lines are drawn from it tomore than one advantage
3
9
(b) escape (predators)
accept faster than swimming
allow chase prey
allow it stops them from drowning1
(c) food1
territory1
deduct one mark for each tick in excess of two
[6]
(a) place all the quadrats randomly on the lawn110
(b) (i) 1 4
2 2
3 2
4 0
all 4 counts correct1
Total = 15
total correct for their figures1
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(ii) 1.5
allow ecf from (b)(i)1
(iii) 180
correct answer with or without working
if answer incorrect, allow 1 mark for x 120 or 15 x 20
or x 12 x 10
or 1.5 x 12 x 10 or 1.5 x 120
allow ecf from (b)(ii)
allow 1 mark if only 1 error2
(c) use a larger sample size / more quadrats
ignore repeats but allow repeat in different places
ignore ‘count them all’
or
use bigger quadrats1
[7]
(a) (placed) randomly
allow description of placement1
11
sufficient number (of quadrats) used1
count (dandelions) in each quadrat1
use mean number of dandelions, area of quadrat and area of field to estimate population
accept (area of field / area quadrat) × mean number of dandelionsper quadrat
1
(b) (40 × 145) / 0.25 = 23 2001
(0.42 × 23 200 =) 9744
allow 9744 with no working shown for 2 marks
allow ecf from correct attempt at the previous step) × 0.42 for 1mark
1
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(c) Level 2 (3–4 marks):A detailed and coherent explanation is given. Logical links between clearly identifiedrelevant points are made to explain why dandelion growth may be limited.
Level 1 (1–2 marks):Discrete relevant points are made. The logic may be unclear.
0 marks:No relevant content
Indicative content
factors that may be considered:competition for resources including:• light• water• space• mineral ions (allow nutrients / salts / ions from the soil)
reference to why growth may be limited:• (light) energy for photosynthesis• water as a raw material for photosynthesis / support• surface area exposed to light• sugar / glucose produced in photosynthesis• (space) to grow bigger• (space) for growth of root system• (mineral ions) for growth• (mineral ions / sugar) for production of larger molecules or named example
4
[10]
(a) wolves112
(b) moose and wolves are on different scales1
(c) wolf population has increased so more moose are eaten
do not accept there are more wolves than moose1
(d) any two from:
• (other) predators
allow correct examples
allow ‘humans hunting moose’• (new) pathogens
allow diseases• competition
2
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(e) any four from:
• variation (within species) of antler size
allow description relating to antlers• (caused by) different genes• as a result of sexual reproduction / process of meiosis / mutation• (phenotype) most suited to environment most likely to survive and breed
ignore natural selection unqualified• genes for large antlers (more likely to be) passed on to next generation
4
reference to mate selectionorfightingorgaining territoryorcompetition for matesoravoiding predation
1
[10]
(a) (i) counts / 121
× 120 × 80 / × 9600or× area of field
1
(ii) (more) quadrats / repeats1
placed randomly
ignore method of achieving randomness1
13
(b) (i) any three from:• temperature / warmth / heat• water / rain• minerals / ions / salts (in soil)
allow nutrients / fertiliser / soil fertility
ignore food• pH (of soil)• trampling• herbivores
ignore predators• competition (with other species)• pollution qualified e.g. SO 2 / herbicide• wind (related to seed dispersal).
ignore space / oxygen / CO2 / soil unqualified3
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(ii) light needed for photosynthesis1
for making food / sugar / etc.1
effect on buttercup distribution eg more plants in sunny areas / fewer plants inshady areas
1
(c) (i) fertiliser / ions / salts cause growth of algae / plants1
(algae / plants) block light1
(low light) causes algae / plants to die1
microorganisms / bacteria feed on / break down / cause decay of organicmatter / of dead plants
do not allow germs / viruses1
(aerobic) respiration (by microbes) uses O2
do not allow anaerobic1
(ii) sewage / toxic chemicals / correct named example eg metals / bleach /disinfectant / detergent etc
allow suitable named examples eg metals such as Pb / Zn / Cr / oil /SO2 / acid rain / pesticides / litter
ignore chemicals unqualified
ignore waste unqualified
ignore human waste / domestic waste / industrial waste unqualified1
(d) (i) 21
(ii) more food
allow other sensible suggestion eg more species colonise fromtributary streams after forest
1
(iii) number of stonefly species decreases (from A to B / B to C / A to C) as morepollution enters river / less oxygen
allow fewer species in more polluted water
ignore none are found at site C1
[19]
(a) photosynthesis114
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(b) (i) 1401
(ii) (10 billion tonnes) more added (to atmosphere) than removed
allow ecf from part (b)(i)1
[3]
(a) gets more light (near surface)
allow warmer (near surface)
allow bladders contain (more) carbon dioxide1
15
(so) photosynthesises more1
(because) bladders aid floating (when tide is in)
or
(so) more biomass / glucose / starch produced
ref to ‘more’ needed only once, eg gets more light forphotosynthesis gains two marks
if ‘more’ not given do not award mark on the first occasion1
(b) lets angler fish see / attract its prey / mates or see predators as it is dark (at 1000m)orlets angler fish see / attract prey to get foodorlets angler fish see / attract mates to reproduceorlets angler fish see predators to avoid being eaten
must be in a correct pair to gain two marks2
[5]
(a) any two from:• (volume of) peat compost has been steady and then declined or volume of peat
compost has declined since 2005
allow 2007 instead of 2005• (volume of) peat-free compost has increased (since 1999)• (volume of) peat is higher than peat-free until 2005, then peat-free compost is
higher (than peat)
allow 2007• total volume of peat and peat-free compost has increased.
2
16
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(b) increases carbon dioxide (in the atmosphere)
ignore methane1
(c) any one from:• reduces biodiversity• destruction of habitats• disruption of food chains.
1
[4]
(a) any three from:
• parts of organisms have not decayed
accept in amber / resin
allow bones are preserved• conditions needed for decay are absent
accept appropriate examples, eg acidic in bogs / lack of oxygen• parts of the organism are replaced by other materials as they decay
accept mineralised• or other preserved traces of organisms, eg footprints, burrows and rootlet
traces
allow imprint or marking of organism3
17
(b) (i) teeth for biting (prey)
must give structure + explanation1
claws to grip (prey)
accept sensible uses1
wing / tail for flight to find (prey)1
(ii) any two from:
• new predators• new diseases• better competitors• catastrophe eg volcanic eruption, meteor• changes to environment over geological time
accept climate change
allow change in weather• prey dies out or lack of food
allow hunted to extinction2
[8]
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(a) (i) correct bar heights
three correct 2 marks
two correct 1 mark
one or none correct 0 marks
ignore width2
18
(ii) (Stream Y)
has many sludge worms / bloodworms
or
has no mayflies / caddis or few shrimp
allow 1 mark if invertebrate not named but correct association given1
which indicate medium or high pollution1
(b) (i) suspended solids increase (as a result of sewage overflow)1
then decrease downstream / return to original levels1
oxygen levels decrease (after sewage overflow)1
and then rise again1
(ii) any three from:
• mayflies decrease (to zero) near overflow
accept ‘have died out’• because oxygen is low or mayflies have high oxygen demand• mayflies repopulate / increase as oxygen increases again• can’t be sure if dissolved oxygen or suspended solids is the cause
3
(c) they respire / respiration
aerobic respiration gains 2 marks1
this requires / uses up the oxygen1
[13]
(a) (i) chloroplast119
(ii) cell wall1
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(b) (i) osmosis
accept diffusion1
(ii) cell wall (prevents bursting)1
(c) (i) carbon dioxide
allow correct formula1
glucose
allow sugar / starch1
(ii) any two from:
• light sensitive spot detects light• tells flagellum to move towards light• more light = more photosynthesis
2
(d) (cell has) larger SA:volume ratio1
short (diffusion) distance
allow correct description1
(diffusion) via cell membrane is sufficient / good enough
or
flow of water maintains concentration gradient1
[11]
(a) any one from:
• get lots of data
accept more reliable / reproducible
do not accept more accurate• cheap / free• unlikely to be biased• can cover a wide area at the same time / takes less time• see seasonal variations
1
20
(b) (i) correct bar heights
1 mark for each correct bar
ignore width of bars2
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(ii) 12 800
(16000 / 100)x80 on its own for 1 mark2
(iii) goldfinch1
(c) any one from:
• more food available
accept fewer predators• people feed them
accept less habitat / food in countryside• more rubbish / waste to eat
1
[7]
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