You are a geneticist studying a newly discovered disease. The disease follows a pattern of maternal inheritance, and both male and female children are affected. Strangely, within a family, all the children are affected, but to very different degrees. What could explain this variation?
a)The disease is caused by a mitochondrial mutation and the variation is due to heteroplasmy.
b) The disease is caused by a mitochondrial mutation and the variation is due to imprinting.
c) The disease is caused by a nuclear mutation and the variation is due to maternal effect.
d) The disease is caused by a nuclear mutation and the variation is due to X-chromosome inactivation.
