If a mother carries a recessive allele for a genetic disorder, such as cystic fibrosis, under what circumstances will her children inherit the disorder?

The children's father must also carry the recessive allele.

The mother's father must also carry the recessive allele

The paternal grandfather must also carry the recessive allele.

The children must be female like the mother to inherit the disorde

Question

If a mother carries a recessive allele for a genetic disorder, such as cystic fibrosis, under what circumstances will her children inherit the disorder?

The children's father must also carry the recessive allele.

The mother's father must also carry the recessive allele

The paternal grandfather must also carry the recessive allele.

The children must be female like the mother to inherit the disorde

anonymous · Answer

Sure - the gene associated with CF is on chromosome 7, rather than on a sex chromosome. This means that the condition will arise if the father is also a carrier of the disease (or has both recessive alleles and has CF). One in four offspring would get CF if two carriers were parents whereas three out of four would have the disease if someone with CF and someone who carried the disease had offspring.

agreene · Answer

The children's father must also carry the recessive allele.