People with achondroplastic dwarfism are heterozygous for a dominant allele conferring this trait. The homozygous dominant condi
tion for the achondroplasia allele is lethal. What is the probability that two people with achondroplastic dwarfism will have a surviving child with this trait?
The allele for dwarfism - D its dominant Recessive allele -d If the person has heterozygous alleles -Dd the person will have achrondroplastic dwarfism However if the person if homozygous for the allele DD it’s Lethal and person can’t survive If both parents are Dd Dd X. Dd Offspring DD Dd Dd dd Probability of children who survive with the trait have the genotype Dd Probability - 1/4 + 1/4 Probability of having surviving children with the trait -1/2 -0.5
