Difference between revisions of "GCSE Biology Required Practical: Measuring Population in a Habitat"
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Estimate the size of a [[population]] of a [[species]] within a [[habitat]] using [[Sampling (Biology)|sampling]] techniques and investigate a factor affecting [[population]] size. | Estimate the size of a [[population]] of a [[species]] within a [[habitat]] using [[Sampling (Biology)|sampling]] techniques and investigate a factor affecting [[population]] size. | ||
===Method=== | ===Method=== | ||
− | + | Estimate the population of a species within a habitat using random sampling. | |
− | # | + | #Place a quadrat in a random location in a field. (''Exam boards apparently do not allow throwing of the quadrat, even though this would reduce bias in the choice of sample space.'') |
#Count the number of daisies within the quadrat. | #Count the number of daisies within the quadrat. | ||
#Repeat steps 1 and 2 ten times. | #Repeat steps 1 and 2 ten times. | ||
Line 10: | Line 10: | ||
#Use the following equation to estimate the number of daisies in the field: | #Use the following equation to estimate the number of daisies in the field: | ||
: Estimated population = <math>\tfrac{area sampled}{total area}</math> x number of daisies | : Estimated population = <math>\tfrac{area sampled}{total area}</math> x number of daisies | ||
+ | |||
+ | Investigate the effect of a factor on plant distribution using a transect. | ||
+ | #Stretch a 30m tape from the base of a tree out into an open area of field. This will be the transect. | ||
+ | #Place a quadrat at 0m on the transect and count the number of daisies within the quadrat. | ||
+ | #Repeat step 2 six times moving the quadrat 5m further along the transect each time. | ||
+ | #At each location you may measure the light intensity, soil hydration or soil [[pH]] to determine if this factor affects the abundance of daisies. | ||
+ | ===References=== | ||
+ | ====Edexcel==== | ||
+ | :[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Biology core practicals; quadrats and transects, pages 128-129, GCSE Combined Science, Pearson Edexcel ''] |
Latest revision as of 14:03, 19 June 2022
Contents
Key Stage 4
Meaning
Estimate the size of a population of a species within a habitat using sampling techniques and investigate a factor affecting population size.
Method
Estimate the population of a species within a habitat using random sampling.
- Place a quadrat in a random location in a field. (Exam boards apparently do not allow throwing of the quadrat, even though this would reduce bias in the choice of sample space.)
- Count the number of daisies within the quadrat.
- Repeat steps 1 and 2 ten times.
- Calculate the mean number of daisies.
- Use the following equation to estimate the number of daisies in the field:
- Estimated population = \(\tfrac{area sampled}{total area}\) x number of daisies
Investigate the effect of a factor on plant distribution using a transect.
- Stretch a 30m tape from the base of a tree out into an open area of field. This will be the transect.
- Place a quadrat at 0m on the transect and count the number of daisies within the quadrat.
- Repeat step 2 six times moving the quadrat 5m further along the transect each time.
- At each location you may measure the light intensity, soil hydration or soil pH to determine if this factor affects the abundance of daisies.