Question

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?

Answer 1

Answer;

The allele that causes achondroplasia is a recessive lethal allele.

Step-by-step explanation;

Achondroplasia is a bone growth disorder that causes disproportionate dwarfism. Dwarfism is defined as a condition of short stature as an adult. People with achondroplasia are short in stature with a normal sized torso and short limbs. It's the most common type of disproportionate dwarfism.

-Achondroplasia is a recessive lethal gene. Recessive lethal genes can code for either dominant or recessive traits, but they do not actually cause death unless an organism carries two copies of the lethal allele.

Answer 2

The achondroplasia is a condition, in which a bone growth disorder cause the condition of disproportionate dwarfism. In humans, this character is inherited as Autosomal dominant trait.

For a person to be normal, the genotype must be homozygous recessive. In case, the person have atleast a single allele for the trait, he or she would be affected.

In this case 2 children are affected, but 1 is normal, which means both the parents are carrier of a recessive allele. Hence, the parents are heterozygous for the trait.

So, it can be concluded that the achondroplasia is an autosomal dominant disease and the individuals in the question are heterozygous.