Genes in the genomes of organelles, specifically plastids and mitochondria, do not behave in a Mendelian fashion.
learning outcome
You should be able to:
Predict inheritance patterns of genes present in organelles.
A disease called Leber’s hereditary 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 mated with a woman who did not have the disease? What would be the result if the wife had the disease and the husband did not?
Because the gene is carried on mitochondrial DNA, it is passed through the mother only. Thus if the women does not have the disease but her husband does, their child will not be affected. However, if the woman has the disease but her husband does not, their child will have the disease.
Mendel and those who followed him focused on eukaryotes, with diploid organisms and haploid gametes. A half-