CAIE A Level Biology 9700 · Classification, biodiversity and conservation
In a marine protected area, an invasive species of alga, Caulerpa taxifolia, has been accidentally introduced. The alga grows rapidly, forms dense mats that smother native seagrasses and corals, and is avoided by native herbivores due to chemical defences. Conservationists are planning a control programme to eradicate or manage the alga. Explain why the invasion of Caulerpa taxifolia must be controlled to protect native biodiversity.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.