People with acho ndroplastic dwarfism are heterozygous for a dominant allele conferring this trait. The homozygous dominant condition for the acho ndroplasia allele is lethal. What is the probability that two people with acho ndroplastic 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 achro ndroplastic 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