One breed of dog has been selectively bred for a very short face. A study found that 1 in every 4 dogs of this breed also has an inherited eye disorder. The eye disorder is caused by a recessive allele.
Explain why selective breeding has increased the number of dogs of this breed that have the eye disorder.
A new disease appears that affects dogs. Explain why this breed of dog is at greater risk from the new disease than a population of wild dogs.
44 exam-style questions on AQA GCSE Biology 6.2 Variation and evolution, covering 6.2.1 Variation, 6.2.2 Evolution, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, and 6.2.5 Cloning. Each one has a worked solution and a mark scheme showing where the marks go.