Answer:
Nn
Explanation:
Tay-Sachs disease is an inheritable genetic disorder that results in the destruction of nerve cells in the brain and spinal cord. It's caused by the absence of an enzyme that helps break down fatty substances called gangliosides. Their buildup results in the destruction of nerve cells.
Tay-Sachs is inherited in an autosomal recessive manner. This means that a person needs to have two recessive alleles (nn) in order to inherit it. Rebecca is a carrier of the disease but isn't actually ill. This means that she has one recessive (n) and one dominant (N) allele. Thus, her genotype is Nn.
