6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
In a woodland, carbon is constantly recycled between the living organisms and the environment through the carbon cycle.
Describe how carbon is recycled in an ecosystem. In your answer, refer to photosynthesis, respiration, feeding and decomposition. (6 marks)
A student estimated the number of daisies in a school field of area 150 m² using a quadrat of area 0.25 m². They placed the quadrat at eight random positions and counted the daisies in each:
3, 5, 4, 6, 2, 5, 4, 3
Use the equation: estimated population=area of one quadrattotal area of habitat×mean number per quadrat
(a) Calculate the mean number of daisies per quadrat. (1 mark)
(b) Estimate the total number of daisies in the whole field. Show your working. (2 marks)
(c) Explain why the quadrats were placed at random positions. (1 mark)
A red squirrel and a grey squirrel live in the same woodland. They both eat nuts and seeds and both nest in tree holes. Since grey squirrels arrived, red squirrel numbers have fallen.
(a) Name the type of competition happening between the red and grey squirrels (they are different species). (1 mark)
(b) Suggest two resources the two species of squirrel are competing for. (2 marks)
A camel lives in a hot, dry desert. It has several adaptations that help it survive there.
(a) State what is meant by an adaptation. (1 mark)
(b) The camel has long eyelashes and can close its nostrils. Suggest two other features that would help a camel survive in a hot, dry environment, and for each explain how it helps. (2 marks)
A wildlife charity is trying to protect the biodiversity of a wetland.
(a) State what is meant by biodiversity. (1 mark)
(b) Suggest one reason why maintaining high biodiversity is important for the stability of an ecosystem. (1 mark)
The diagram shows part of a food web:
grass → grasshopper → frog → snake
Name the producer in this food chain. (1 mark)