Ecologists want to estimate the mean percentage cover of bladderwrack seaweed across a flat rocky platform. They have quadrats, a transect and a random number generator available.
Which sampling plan would give an unbiased estimate of the abundance of bladderwrack across the rocky platform?
Use quadrats only at positions where bladderwrack is visible.
Use the transect and record where bladderwrack is present.
Use the transect only through positions with dense bladderwrack.
Use quadrats at positions selected using the random number generator.
83 exam-style questions on AQA GCSE Biology 7.2 Organisation of an ecosystem, covering 7.2.1 Levels of organisation, 7.2.2 How materials are cycled, 7.2.3 Decomposition, and 7.2.4 Impact of environmental change (HT only). Each one has a worked solution and a mark scheme showing where the marks go.