Agapanthus is a dominant, homozygous lethal trait among Telorites from the plane
ID: 65482 • Letter: A
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 three F2 individuals, we only observe the wild-type phenotype. The genotype of the randomly-selected F1 subject must be:
A. AA.
B. aa.
C. Aa.
D. We cannot say with certainty. We need to perform a Chi-square goodness of fit test.
E. Aa or aa.
Explanation / Answer
The genotype of randomly selected F1 subject must be AA because parents itself is Agapanthus (homozygous dominant) having genotype (AA) and True breeding wild type (AA).