Tay Sachs is a lysosomal storage disease that is inherited in an autosomal recessive manner.Individuals with Tay Sach have a defect in the gene encoding hexosaminidase A,a lysosomal enzyme that breaks down cell membrane components called gangliosides.The inability to break down gangiosides causes harmful quantities of this lipid to accumulate in nerve cells of the brain,eventually leading to premature death of affected cells.There is no known cure for the disease,and death usually occurs by age 4.(T= dominant allele;t = recessive allele)Jack and Jill have a child who has Tay-Sachs.What do you know about the genotypes of Jack and Jill?
A)Both are heterozygous
B)One is TT and the other is tt
C)Both are TT
D)Both are tt
E)It's impossible to tell.Since both are adults,they do not have the diseasE.But,they could either be TT or Tt

Question

Quizplus · Accepted Answer

Both Jack and Jill must be heterozygous (Tt) to have a child with Tay-Sachs, as the disease is autosomal recessive and requires two recessive alleles (tt) for the child to express the disease.

Tay Sachs Is a Lysosomal Storage Disease That Is Inherited