AQA GCSE Biology

Speciation

AQA GCSE Biology revision on Speciation. Aligned to the AQA GCSE Biology 8461 specification. This bank has 25 practice questions on this topic.

Sample questions (3 of 25)

Question 1

Which mechanism initially separates a single population into two distinct groups during the process of speciation?
- A) Genetic mutation
- B) Geographical barrier
- C) Selective breeding
- D) Rapid extinction
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Answer: Geographical barrier

For speciation to occur, gene flow between populations must be restricted. A physical barrier, such as a mountain range or a river, creates geographical isolation, allowing the two groups to evolve independently over time.
Question 2

What is the primary biological outcome when two isolated populations can no longer interbreed to produce fertile offspring?
- A) Increased variation
- B) Formation of species
- C) Hybrid vigour gain
- D) Common gene pools
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Answer: Formation of species

The biological definition of a species relies on the ability to interbreed and produce fertile offspring. If genetic and phenotypic differences accumulate to the point where this is impossible, the groups are considered separate species.
Question 3

Which factor drives the divergence of two isolated populations after they have been separated by a physical barrier?
- A) Identical mutations
- B) Natural selection
- C) Uniform environment
- D) Shared gene flow
Show answer

Answer: Natural selection

Once isolated, different environments exert unique selective pressures. Natural selection favours different traits in each location, leading to distinct genetic changes that eventually make the two groups reproductively incompatible.

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22 more questions on Speciation — plus mistakes tracking and spaced repetition across the whole Biology spec.

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