Which of the following cases would represent lethal alleles in the case of Achondroplasia, a common cause of dwarfism in humans? All individuals with achondroplasia are thought to be heterozygous at the locus that controls this trait. When two individuals with achondroplasia mate, the offspring occur in a ratio of 2 achondroplasia: 1 normal. What is the MOST likely explanation for these observations? The phenotype coded by the dominant allele is only expressed in homozygous individuals. The resulting cross of two heterozygote parents has 3 possible phenotypes. The resulting cross of a homozygous dominant and a homozygous recessive gives a single phenotype. The resulting cross of two heterozygous parents does not have any homozygous offspring for one of the alleles.

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