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Investigating variation

Variation within a species can be investigated. For example, if you were asked to find out if there was a link between the length of a pea pod and the number of seeds inside the pod you could:

  • measure the length of a range of pea pods
  • count the peas inside.

The experiment is made valid by controlling the variables.

The independent variable is length of the pea pod.

The dependant variable is the number of peas.

The control variables include:

  • variety of pea plant
  • time of year that the peas are selected.

The experiment is made reliable by further testing and achieveing a repeat of your results.

Back to Classification, inheritance and variation index

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