Final Answer:
In this case, all the children will be heterozygous (genotype OP) and will express the dominant orange hair phenotype.Therefore, none of their children will have purple hair, as the orange hair allele is dominant. The percentage of their children with purple hair is 0%.
Step-by-step explanation:
In genetics, the inheritance of traits is determined by alleles, different forms of a gene. In this scenario, Krull having orange hair means he carries two alleles for orange hair (OO), and Jizbah having purple hair means she carries two alleles for purple hair (PP).
When they have children, each child inherits one allele from each parent. However, the allele for orange hair (O) is dominant over the allele for purple hair (P). Therefore, all the children will inherit one orange hair allele from Krull and one purple hair allele from Jizbah (heterozygous, OP). The dominant orange hair allele will be expressed, so none of the children will actually have purple hair. Therefore, the percentage of their children with purple hair is 0%.