In a cattle breed, a harmful condition is caused by a recessive allele. Two closely related animals selected for high milk yield both carry this allele.
Which statement explains a risk of breeding these animals together?
An offspring may inherit the harmful allele from both parents and develop the condition.
The close relationship may change the harmful allele into a new allele in the offspring.
An offspring may inherit the harmful allele from one parent and always develop the condition.
The high milk yield may change the harmful allele into a dominant allele in the offspring.
44 exam-style questions on Edexcel GCSE Biology 4.3 Selective breeding and genetic modification, covering 4.3.1 Selective breeding and its impact, 4.3.2 Tissue culture, 4.3.3 Genetic engineering overview, 4.3.4 Main stages of genetic engineering, 4.3.5 Advantages and disadvantages of GM organisms, 4.3.6 Agricultural solutions for a growing population, and 4.3.7 Evaluating genetic engineering and breeding. Each one has a worked solution and a mark scheme showing where the marks go.