Question

In two separate Punnett squares explain the possible outcomes for the children of two different sets of parents as follows: Set A parents are both carriers of Huntingdon’s Disease, and in Set B only one parent is a carrier of Huntingdon’s Disease. Explain the results of each Punnett Square

Answer 1

Huntington's disease is caused by a dominant allele written as H.

Case 1. When both the parents are carrier in Huntington disease one can never be a carrier. They either have it or not.

All the children may inherit Huntington disease or none at all.

Father carrier - hh^o

mother carrier -hh^o

possible outomes - hh, hh^o, h^oh^o, hh^o

Therefore - hh and h^oh^o are unaffected  

hh^o - carrier

Case 2 : when one is a parent is carrier

hh^o (cacarrier) crossed with hh (unaffected)

Possible outcome hh, hh^o, hh and hh^o

^{hence 2 are carrier and 2 are unaffected.}