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Ecosystems

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Question 3

Ecological succession is a directional change in community structure over time. Which statement regarding succession and ecosystem stability is not correct?

A

Pioneer species are adapted to tolerate extreme abiotic conditions, and their death and decomposition help build up an organic soil layer that makes the habitat less hostile.

B

Secondary succession is initiated on completely sterile substrates, such as newly exposed rock from a retreating glacier, where no organic matter or soil remains.

C

In a climax community, a stable equilibrium is reached where the rate of gross primary productivity is approximately balanced by total community respiration.

D

As succession proceeds, species diversity typically increases, which increases the number of niches and creates more complex food webs.

Markscheme

Ecosystems Questions

  1. A Level
  2. /Biology
  3. /Ecosystems

37 exam-style questions on OCR A A Level Biology Ecosystems. Each one has a worked solution and a mark scheme showing where the marks go.

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