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Specimen lab book: Field investigations
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Study Hack Lab
RP 9 · Biology
Field investigations
Lab book
Name
Specimen
Date
2 November 2026
Course
GCSE Biology
Board and specification
AQA GCSE Biology (8461), 4.7.2.1AQA GCSE Combined Science: Trilogy (8464), 4.7.2.1Apparatus and techniques: AT 1, AT 3, AT 4, AT 6, AT 8
Run
C29HO
Status
Finished: every stage done
Exam questions
30/30 marks
Aim
Estimate the population of daisies in part of the school field using random quadrats, and use a transect to investigate how light intensity affects their distribution away from a tree.
Contents
Plan and risk assessment
Apparatus
Method
Results
Graph
Analysis
Conclusion and evaluation
Make safe and clear up
Exam questions on your data
Simulated data produced by Study Hack Lab from the student's own run (seed 20261004). Every reading, value and mark here is from that run; nothing has been retyped. Layout v1, practical v2. Original material; not affiliated with AQA, which has not reviewed it.
1 Plan and risk assessment
You cannot count every daisy in a field, so you count them in a sample of small areas (quadrats) and scale up. Placing the quadrats at random makes the sample represent the whole plot. To see how a factor such as light affects where a species grows, you sample along a line across the change (a transect) and measure the factor at each quadrat.
population = mean number per m² × area of the habitat
Variables
Independent (you change)
Distance from the tree (and so the light intensity) in m
Dependent (you measure)
Number of daisy plants in each quadrat
Control (you keep the same)
Size of quadrat; Counting rule; Time of the light readings; Same person counting
Prediction
How do you think the number of daisy plants will vary from one random quadrat to the next?
A lot: some quadrats will have none, others ten or more, because daisies grow in patches.Right first time
Your quadrats held from 0 to 12 daisy plants. Daisies spread by seed and by short side shoots, so new plants grow close to the old ones. They also grow poorly in deep shade, and some parts of a field are bare or worn. So the numbers in quadrats vary a lot, which is why you need many quadrats and a mean.
Along the transect from the tree out into the open field, where will you find the most daisy plants?
Far from the tree, in the open, where there is most light.Right first time
You counted 1 at 0 m and 4 at 12 m. Daisies are short plants that need plenty of light for photosynthesis. Under the tree its leaves block most of the light (and its roots take water), so fewer daisies grow there.
How will the light intensity change along the transect?
It will be low under the tree and rise as you move into the open, then stay about the same.Right first time
Your light meter read 11 090 lux at 0 m and 42 960 lux at 12 m. The tree’s crown blocks direct sunlight. Once you are out of its shadow the ground gets full daylight, so the light intensity rises and then levels off.
Risk assessment
Hazard
Harm it could cause
Control you chose
Throwing a metal quadrat
It can hit someone and cut or bruise them, or injure an eye
Never throw a quadrat. Carry it and place it at the coordinates.Right first time
Broken glass, sharp litter or dog mess in the grass
Cuts to knees and hands; infection
Walk over the site and check it before you start; report anything you find and keep away from it.Right first time
Wet grass and uneven ground
Slipping, twisting an ankle
Walk, do not run; do not work outside in very wet conditions.Right first time
A long tape springing back into its case
The metal end or edge can cut a hand
Lock the tape while it is laid out and rewind it slowly with your fingers clear.Right first time
Soil on your hands; bees and wasps on flowers
Infection through a cut; stings (and an allergic reaction)
Cover cuts, wash your hands after; tell the teacher about any sting allergy and leave insects alone.Right first time
2 Apparatus
✓Quadrat, 50 cm × 50 cm (0.25 m²), strung into 25 squares (resolution 0.25 m²) Marks out the same area to count in each time.
✓Two 30 m tape measures (resolution 1 cm) Laid at right angles along two sides of the plot as the axes of a grid.
✓A third 30 m tape measure (resolution 1 cm) The transect line from the tree out into the open.
✓Calculator with a random number key Gives the random coordinates.
✓Digital light meter (lux meter) (resolution 10 lux) Measures the light intensity at each quadrat on the transect.
✓Identification card Shows a daisy plant, so it is not confused with dandelion or plantain.
✓Clipboard, pencil and results table Records each count and reading at once.
3 Method: your choices
Which version are you doing?: AQA required practical 9: quadrats and a transectA quadrat every 2 m along the transect from the tree.
Walk over the site firstSafety: DoneYou will kneel and put your hands in the grass. Anything sharp or dirty needs to be found and reported first.
Choose where each quadrat goes: Two tapes at right angles along two sides of the plot, and a random number generator to give the coordinatesEvery part of the plot has the same chance of being sampled, so the estimate is not biased. It still varies by chance, because daisies grow in patches.
Choose how many quadrats to use: Ten quadratsTen random quadrats usually give a population within about ±30 % of the true value: patchy plants vary a lot from quadrat to quadrat.
Choose where along the tape to place the quadrats: At regular intervals: every 2 m from 0 m to 12 mThe whole line is sampled evenly, so the pattern from shade to light is clear.
What do you count?: Whole plants: each rosette of leaves counts onceEach plant is counted once, so your count is the number of plants.
Plants on the edge: Count plants touching the top and left sides; leave out those touching the bottom and right sidesPlants on the edge are counted only half the time, so on average the count matches the number of plants growing in 0.25 m².
When to take the light readings: Take all seven readings quickly, one after another, on the same dayThe sun is the same for every reading, so the light readings differ only because of the tree.
4 Results
24 of 24 readings taken.
Daisy plants in random quadrats · Each quadrat goes down with its corner at the coordinates the random numbers give, measured along the two tapes.
Quadrat
x coordinate in m
y coordinate in m
Number of daisy plants
1
7.5
7.5
9
2
5.0
1.5
0
3
7.5
3.0
7
4
1.5
0.5
10
5
5.5
4.0
6
6
3.5
0.5
2
7
2.5
6.0
5
8
4.5
3.0
5
9
5.5
7.5
8
10
1.0
6.5
12
Along the transect from the tree · A quadrat every 2 m along the tape, its corner on the tape. Count the daisy plants, then read the light meter on the ground in the middle of the quadrat.
Distance from the tree in m
Number of daisy plants
Light intensity in lux
0
1
11090
2
0
7640
4
4
9570
6
1
15280
8
15
35500
10
8
43610
12
4
42960
Anomaly: No anomalous reading.
5 Graph
Daisies along the transectLight along the transect
6 Analysis
Mean per quadrat
mean = total of the counts ÷ number of quadrats
Calculate the mean number of daisy plants per quadrat from your 10 counts.
6.4 plantsRight first time
Median
Put the counts in order; the median is the middle one (or halfway between the middle two).
Find the median number of daisy plants per quadrat.
6.50 plantsRight first time
A quadrat with few daisies
Quadrat 2 landed on the worn path across the plot and had 0 daisy plants. What do you do with it?
Keep it in the mean: that part of the plot really has few daisies, so it is real data.Right first time
Mean per m²
A 50 cm × 50 cm quadrat is 0.5 m × 0.5 m = 0.25 m², so there are 4 quadrats in 1 m².
Calculate the mean number of daisy plants per m².
25.6 plants per m²Right first time
Estimated population
population = mean number per m² × area of the plot
The plot is 10 m long and 8 m wide. Estimate the number of daisy plants in the plot.
2048 plantsRight first time
Chance and the number of quadrats
2 of 2 right first timeRight first time
Shape of the graph
Describe how the light intensity changes along the transect.
Low under the tree, rising steeply where its shadow ends, then levelling off in the open.Right first time
Light and daisies
Use your transect results. How does the number of daisy plants change with light intensity?
Where the light intensity is higher, there are more daisy plants.Right first time
Does it prove light is the cause?
Consider your recorded counts and light readings along the transect. Can this observational investigation alone prove that light causes the distribution of daisies?
No: other factors also change along the line (soil water, the tree’s roots, how trampled it is), so light may not be the only cause.Right first time
7 Conclusion and evaluation
Quantity
Your value
Accepted value
Daisy plants in the plot (drone photo: every plant counted)
2050 plants
1820 plants
Mean daisy plants per 0.25 m² (the whole plot)
6.4 plants
5.7 plants
Conclusion
What do your results show? Pick everything that your data support.
Scaling the 10-quadrat sample gives about 2000. This is an estimate, whose validity depends on representative sampling and counting whole plants. The recorded transect compares plant counts and light, but does not isolate light as a cause of the distribution.Right first time
Scaling sample counts gives an estimate, not an exact census. Representative sampling and whole-plant counts matter. Describe the trend actually recorded; other factors vary along the transect, so it does not by itself prove a causal effect of light.
Sources of error
Placing the quadrats by throwing them or by choosing places: systematic or random?
SystematicRight first time
Quadrats land in the patches of flowers more often than chance would put them there, so the mean and the population are too high (biased).
Too few quadrats in a patchy field: systematic or random?
RandomRight first time
The mean depends on whether the few quadrats happened to land on patches or on bare ground, so the estimate could be far too high or too low.
Counting every plant that touches the frame: systematic or random?
SystematicRight first time
Plants on the edge are counted in every quadrat they touch, so every count and the population are too high.
Counting flower heads instead of whole plants: systematic or random?
SystematicRight first time
Each plant has one to three flowers, so the counts are about double the number of plants.
The daisies grow in patches (sampling error): systematic or random?
RandomRight first time
Even random quadrats give a mean a little different from the true mean, so the population is an estimate.
Light readings taken at different times: systematic or random?
RandomRight first time
Clouds change the light from minute to minute, so readings differ for reasons that have nothing to do with the tree.
Quadrats at random distances along the transect: systematic or random?
RandomRight first time
Parts of the line are missed and others sampled twice, so the change from shade to light is unclear.
One transect from one tree: systematic or random?
RandomRight first time
One line can pass a patch or a bare area by chance, and other factors change along it too (soil water, trampling), so one line cannot show that light is the cause.
Improvement
Which change would most improve your results?
Use more quadrats, or larger ones, so more of the plot is sampled.Right first time
Repeatable or reproducible
You laid the transect again in the same place the next day, with the same quadrat and meter, and got similar counts and readings at each distance. This shows your results are…
RepeatableRight first time
Repeatable: the same person, method and equipment give similar results.
Another class, using a 1 m² quadrat every 5 m from a different tree, also found few daisies in the shade and many in the open. This shows the results are…
ReproducibleRight first time
Reproducible: a different person, method or equipment gives similar results.
8 Make safe and clear up
Pick up the quadrat
Rewind the tapes slowly, keeping fingers clear of the tape as it goes in
Switch off the light meter and put the kit back in the box
Wash your hands with soap and water
9 Exam questions on your data
On your own readings, self-marked against the mark scheme, with error carried forward where it applies. Total 30/30.
01.1[2 marks]
You estimated the population of daisy plants in a 10 m × 8 m plot of the school field using ten quadrats.
Describe how you decided where to place each quadrat, and explain why you did it this way.
Your answer
Two tapes at right angles made a grid and a calculator gave random numbers as the coordinates for each quadrat. This avoids bias so the sample is representative of the whole plot.
2/2 self-marked
Two tapes at right angles (a grid) and random numbers (from a calculator or random number generator) used as coordinates (ignore throwing)
To avoid bias / so the sample is representative of the whole plot / every part of the plot has an equal chance of being sampled
Self-marked: 2 of 2 marks. This is your own judgement against the mark scheme.
Model answer: I laid two tapes at right angles along two sides of the plot to make a grid, and used a random number generator to give the coordinates of each quadrat. This avoids bias, so the quadrats are representative of the whole plot.
01.2[2 marks]
Students did this fieldwork on the school field, kneeling in the grass.
Give one harm that could happen during this fieldwork, and one way to reduce the risk of it.
Your answer
You could cut your knee on broken glass in the grass. Check the area for glass and litter before starting.
2/2 self-marked
Harm: a cut (from glass, litter or a tape) / slipping or falling (sprain) / infection (from soil or faeces) / a sting / being hit by a quadrat (ignore "dangerous" or "hazard" on its own)
Control: check (walk over) the site for glass or litter first / walk, do not run / wash hands after / cover cuts or wear gloves / never throw quadrats / lock and rewind tapes carefully / avoid very wet conditions
Self-marked: 2 of 2 marks. This is your own judgement against the mark scheme.
Model answer: Kneeling on broken glass hidden in the grass could cut you. Walk over the site and check it for glass and litter before you start.
02.1[4 marks]
Your counts in your 10 quadrats were: 9, 0, 7, 10, 6, 2, 5, 5, 8, 12.
Your mean was 6.4 daisy plants per quadrat. Each quadrat was 50 cm × 50 cm. The plot was 10 m long and 8 m wide.
Use your mean to estimate the number of daisy plants in the plot.
Give your answer to 2 significant figures.
Your answer
2000
Working: mean per m2 = 6.4 × 4 = 25.6
area = 10 × 8 = 80 m2
population = 25.6 × 80 = 2048
= 2000 (2 s.f.)
4/4
Mean per m² = 6.4 × 4 (or ÷ 0.25) = 25.6; or 80 ÷ 0.25 = 320 quadrats
Area of the plot = 10 × 8 = 80 m²
2048 daisy plants
2000 (2 significant figures)
Full marks. That is exactly what the mark scheme is looking for.
Model answer: mean per m² = 6.4 × 4 = 25.6
area = 10 × 8 = 80 m²
population = 25.6 × 80 = 2048
= 2000 (2 s.f.)
02.2[2 marks]
A drone photographed the whole plot and every daisy plant in it was counted: 1821 plants.
From your quadrats you estimated 2048 plants.
Suggest one reason why your estimate was higher than the drone count, and explain how it made your estimate too high.
Your answer
The daisies grow in patches and ten quadrats is a small sample, so my counts were too high and the estimate was too high.
2/2 self-marked
A reason that applies to your sample or counting, for example: Daisies grow in patches, so a few quadrats can land on more (or fewer) plants than average by chance: the mean of a sample is not exactly the mean of the whole plot.
Links it to the result: the counts (or the mean) were too high, so the estimate was too high
Self-marked: 2 of 2 marks. This is your own judgement against the mark scheme.
Model answer: Daisies grow in patches, so a few quadrats can land on more (or fewer) plants than average by chance: the mean of a sample is not exactly the mean of the whole plot. So the mean per quadrat was higher than the true mean, and the estimate was too high.
02.3[4 marks]
Another student estimated the number of daisy plants on a lawn. Figure 1 shows the lawn: a right-angled triangle with a rectangle of paving in one corner, where no daisies grow.
The student placed 50 cm × 50 cm quadrats at random. The mean was 6.5 daisy plants per quadrat.
Model answer: per m² = 6.5 × 4 = 26
area = ½ × 16 × 12 − 2 × 3 = 96 − 6 = 90 m²
population = 26 × 90 = 2340
= 2340 (3 s.f.)
03.1[1 mark]
You laid a tape from the trunk of a tree out into the open field. You placed a quadrat at intervals along the tape. At each one you counted the daisy plants and measured the light intensity.
What was the independent variable in the transect investigation?
Your answer
Distance from the tree
1/1 self-marked
Distance from the tree (along the transect) (do not accept light intensity: it was measured)
Self-marked: 1 of 1 mark. This is your own judgement against the mark scheme.
Model answer: The distance from the tree.
03.2[1 mark]
Another student did the same transect investigation. Table 1 shows their results.
Which row contains an anomalous result?
Select one row.
Table 1
Distance from the tree in m
Light intensity in lux
Number of daisy plants
0
10 970
1
2
7790
0
4
10 080
4
6
14 580
1
8
10 150
15
10
43 180
8
12
41 970
4
Your answer
the row at 8 m
1/1
The row at 8 m: its light intensity is far lower than the readings either side
Full marks. That is exactly what the mark scheme is looking for. Look along the light intensity column: at 8 m it does not fit the pattern of its neighbours.
Model answer: The row at 8 m. Its light intensity (10 150 lux) is far lower than the readings either side, as if a cloud covered the sun.
03.3[2 marks]
You laid a tape from the trunk of a tree out into the open field. You placed a quadrat at intervals along the tape. At each one you counted the daisy plants and measured the light intensity.
Table 2 shows your results.
Table 2
Distance from the tree in m
Light intensity in lux
Number of daisy plants
0
11 090
1
2
7640
0
4
9570
4
6
15 280
1
8
35 500
15
10
43 610
8
12
42 960
4
Describe the relationship between light intensity and the number of daisy plants in your results.
Your answer
As the light intensity increases, the number of daisy plants increases: at 7640 lux there were 0 plants but at 43 610 lux there were 8.
2/2 self-marked
As light intensity increases, the number of daisy plants increases (ignore "positive correlation" or "directly proportional" unqualified)
Uses data from the table (a pair of readings) / few or no daisies at low light
Self-marked: 2 of 2 marks. This is your own judgement against the mark scheme.
Model answer: As the light intensity increases, the number of daisy plants increases: at 7640 lux there were 0 plants but at 43 610 lux there were 8.
03.4[2 marks]
Explain why more daisy plants grow where the light intensity is higher.
Your answer
More light means more photosynthesis, so more glucose is made for growth.
2/2 self-marked
More (rate of) photosynthesis
So more glucose (food, sugar, starch, energy) is made for (respiration and) growth / so more plants survive and grow
Self-marked: 2 of 2 marks. This is your own judgement against the mark scheme.
Model answer: More light means a faster rate of photosynthesis, so the daisies make more glucose, which they use for respiration and growth, so more of them grow and survive.
03.5[1 mark]
The light readings should all be taken quickly, one after the other. Suggest why.
Your answer
Because the light intensity could change if a cloud covers the sun.
1/1 self-marked
The light intensity (from the sun) changes over time / clouds may cover the sun / so the only difference is the position (fair test)
Self-marked: 1 of 1 mark. This is your own judgement against the mark scheme.
Model answer: The light intensity changes over time, for example when a cloud covers the sun, so readings taken at different times could not be compared fairly.
03.6[1 mark]
Give one abiotic factor, other than light intensity, that could change along the transect and affect the number of daisy plants.
Your answer
soil moisture
1/1 self-marked
Soil moisture (water) / temperature / soil pH / mineral ions (nutrients) / wind / carbon dioxide (ignore "sun" and "shade"; do not accept biotic factors such as trampling, competition or the tree)
Self-marked: 1 of 1 mark. This is your own judgement against the mark scheme.
Model answer: Soil moisture (the amount of water in the soil).
04[2 marks]
Another student estimated the percentage cover of moss in a quadrat next to the trunk of the tree.
The quadrat was divided into 25 equal squares. Figure 2 shows the quadrat: a square is shaded if it was at least half covered by moss.
Figure 2
Calculate the percentage cover of moss in the quadrat.
Your answer
24
Working: 6 / 25 x 100 = 24
2/2
6 ÷ 25 × 100 (or 6 × 4)
24 (%)
Full marks. That is exactly what the mark scheme is looking for.
Model answer: 6 ÷ 25 × 100 = 24 %
05[6 marks]
A student wants to investigate how light intensity affects the distribution of daisy plants near a tree in the school field.
Describe a method the student could use. You should include how they would collect and use their results.
Your answer
1. Fix a tape measure at the trunk of the tree and lay it in a straight line out into the open field (a transect).
2. Place a quadrat (0.25 m²) against the tape at 0 m, then at regular intervals, for example every 2 m, to 12 m.
3. In each quadrat count the number of daisy plants (whole plants, using a rule for plants on the edge).
4. At each quadrat measure the light intensity with a light meter held at ground level.
5. Take all the light readings quickly, at the same time of day.
6. Repeat with more transects in other directions round the tree (or at other trees) and calculate the mean number of daisies at each distance.
7. Plot the mean number of daisies and the light intensity against distance and compare them.
6/6 self-marked
Lay a tape (transect line) from the tree out into the open
Place quadrats at regular intervals along the line (do not accept random intervals)
Use a quadrat of stated size (0.25 m² or 1 m²)
Count the number of daisy plants in each quadrat
Measure light intensity at each quadrat with a light meter
Take the light readings at the same time / quickly / same day
Repeat with more transects (other directions or trees) and calculate a mean at each distance
Plot or compare the number of daisies with the light intensity (or the distance)
Self-marked: Level 3, 6 of 6 marks. You ticked 8 of 8 indicative points. This is your own judgement against the mark scheme.
Model answer: 1. Fix a tape measure at the trunk of the tree and lay it in a straight line out into the open field (a transect).
2. Place a quadrat (0.25 m²) against the tape at 0 m, then at regular intervals, for example every 2 m, to 12 m.
3. In each quadrat count the number of daisy plants (whole plants, using a rule for plants on the edge).
4. At each quadrat measure the light intensity with a light meter held at ground level.
5. Take all the light readings quickly, at the same time of day.
6. Repeat with more transects in other directions round the tree (or at other trees) and calculate the mean number of daisies at each distance.
7. Plot the mean number of daisies and the light intensity against distance and compare them.
Unseen data: the same skills, new apparatus
01[2 marks]
A separate simulated sample has ten counts: 3, 6, 0, 5, 7, 9, 2, 4, 5, 3. Use its displayed mean and the new plot area.
Mean count = 4.4 per quadrat. Each quadrat covers 0.25 m². The whole plot covers 160 m².
Calculate the population estimate using these values. Give your answer to the nearest whole plant.
Your answer
2816
Working: 4.4 / 0.25 = 17.6
17.6 × 160 = 2816
2/2
Mean per m² = 4.4 ÷ 0.25 = 17.6.
Population estimate = 2816 plants.
Full marks. Clear and precise.
Model answer: 4.4 ÷ 0.25 × 160 = 2816 plants. This estimates a population; sampling does not count every plant.
02[2 marks]
A student estimates plant population by choosing five green patches in a field.
Which two changes would improve the sampling method? Tick (✓) two boxes.
✓ Use random-number coordinates on a grid covering the whole field, placing quadrats at those coordinates. (your choice)
✓ Use more quadrats, with the same quadrat area and whole-plant counting rule. (your choice)
Throw the quadrat towards places with more flowers.
Discard valid zero counts before calculating the mean.
Your answer
Use random-number coordinates on a grid covering the whole field, placing quadrats at those coordinates.; Use more quadrats, with the same quadrat area and whole-plant counting rule.
2/2
Use random-number coordinates on a grid covering the whole field, placing quadrats at those coordinates.
Use more quadrats, with the same quadrat area and whole-plant counting rule.
Full marks. Well done.
Model answer: Random coordinates reduce selection bias. More comparable samples improve representation of variation; include valid zeros. More samples do not guarantee the exact population.
03[2 marks]
In a different investigation, plant counts and measured light both tend to increase away from a tree. Soil water also increases with distance.
Which two statements are justified? Tick (✓) two boxes.
✓ This observed relationship alone does not prove that light caused the change in plant abundance. (your choice)
✓ Repeat transects around several trees, measuring soil water as well as light at each quadrat, to investigate alternative explanations. (your choice)
The trend proves that light is the only factor affecting abundance.
Soil water is automatically controlled because the quadrats have equal areas.
Your answer
This observed relationship alone does not prove that light caused the change in plant abundance.; Repeat transects around several trees, measuring soil water as well as light at each quadrat, to investigate alternative explanations.
2/2
This observed relationship alone does not prove that light caused the change in plant abundance.
Repeat transects around several trees, measuring soil water as well as light at each quadrat, to investigate alternative explanations.
Full marks. Clear and precise.
Model answer: Light and soil water both vary, so causation is not isolated. Repeated transects with both factors measured provide stronger evidence, though an observational study still does not by itself prove a causal effect.