Years of choosing the heaviest sheep as parents have made one flock genetically similar. To introduce disease resistance, a ewe from this flock is mated with a resistant ram from another flock.
Four lambs are reared under the same conditions and exposed to the disease.
| Lamb | Mean daily mass gain in g | Disease response |
|---|---|---|
| A | 320 | developed disease |
| B | 300 | did not develop disease |
| C | 250 | did not develop disease |
| D | 290 | developed disease |
Which lamb should the breeder select to be a parent of the next generation?
Lamb C
Lamb D
Lamb A
Lamb B
100 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.