Question

The disease Leber's optic neuropathy is caused by a mutation in a gene carried on mitochondrial DNA. What would be the phenotype of their first child if a man with this disease married a woman who did not have the disease? What would be the result if the wife had the disease and the husband did not?

Answer 1

Answer: the child's phenotype will be normal.

The child will acquire that disease.

Explanation:

The mitochondrial DNA is a small circular chromosome that exists in the mitochondria. The mitochondria is the power house of the cell and all its 37 DNA are essential for a normal function of the mitochondria. the mtdna is passed directly from the mother (through the egg cell) to the child either a male or female but the son cannot pass his mtdna to his child. Thus, if a man with this disease marries a woman not affected, the child's phenotype will be normal. But if the wife has the disease, this willl be passed from her to her child me it a male or female.