Question

Agapanthus is a dominant, homozygous lethal trait among Telorites from the planet Teleflora. Subjects with this condition love to send flowers. From a group of Telorites heterozygous at the Agapanthus locus (with two alleles: A = dominant (trait) allele, a = recessive (wild-type) allele), 88% of the Telorites have the Agapanthus phenotype, and 12% look wild-type. Also, true-breeding wild-type Telorites (aa genotype) have 0% penetrance. A Telorite with the Agapanthus phenotype mates with a true-breeding Telorite with the wild-type phenotype. One of the F1 children is randomly selected and is mated back to the true-breeding wild-type parent. Out of twenty F2 individuals, we observe the following counts: Eight F2 individuals have the Agapanthus phenotype; Twelve F2 individuals have the Wild-type phenotype. The genotype of the randomly-selected F1 subject must be:

Answer 1

Answer:

Aa

Explanation:

Parents are a Telorite with the Agapanthus phenotype and a true-breeding Telorite with the wild-type phenotype

P: Aa  x aa

F1: Aa Aa aa aa

Phenotype ratios in F2 are 2:3 (Aa:aa). Simce there is Agapanthus phenotype in F2 generation it means that the genotype of the randomly-selected F1 subject is Aa