3 guides on this topic
Ecology
What each ecology question is really asking, how to structure the answer, and where the marks are likely to sit.
Six questions in 250 to 500 words, so about sixty words each. The brief pre-empts the commonest error by telling you the difference between a biome and an ecosystem.
The prompt lists predator-prey among its examples of symbiosis, and it is the one example that is not symbiosis. Choosing a different relationship is the easiest mark here.
Three questions, and the middle one asks for a prediction. Primary succession is the concept that makes it answerable rather than speculative.