View source for GCSE Biology Required Practical: Measuring Population in a Habitat

==Key Stage 4==
===Meaning===
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===
Estimate the population of a species within a habitat using random sampling.
#Gently throw a quadrat to fall in a random position on a field of grass.
#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 = <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 '']