Question

Achondroplastic dwarfism is a dominant genetic trait that causes severe malformation of the skeleton. Homozygotes for this condition are spontaneously aborted (hence, the homozygous condition is lethal) but heterozygotes will develop to be dwarfed. Matthew has a family history of the condition, although he does not express the trait. Jane is an achondroplastic dwarf. Matthew and Jane are planning a family of several children and want to know the chances of producing a child with achondroplastic dwarfism. The genotypes of Matthew and Jane are best represented as _____.

Answer 1

Answer:

Jane: Aa

Matthew: aa

Explanation:

Jane is a heterozygous woman, which means that she is dominant for this genetic trait while Matthew is homozygous that did not inherit the achondroplastic dwarfism trait from his parents, that is why he is alive.

If we draw a Punnett square, we can see that some of their children will inherit the trait while others will not.

  ║ a      ║ a

A  ║   Aa ║Aa

a  ║ aa    ║ aa