Which type of mutation can only be passed down from the mother?

Mitochondrial mutations are unique in that they are inherited exclusively from the mother. This is due to the way mitochondria are transmitted during reproduction. During fertilization, the sperm contributes nuclear DNA but does not pass on its mitochondria to the zygote; the mitochondria are inherited from the egg cell, which is why mitochondrial DNA (mtDNA) is maternal in origin.

Mitochondrial mutations can lead to various inherited metabolic disorders and syndromes that primarily affect energy production in cells, as mitochondria are crucial for generating ATP. These mutations can affect multiple generations of offspring, all of whom will inherit the same mitochondrial DNA from their mother.

In contrast, autosomal dominant mutations can be passed from either parent to offspring, meaning they are not restricted to maternal inheritance. Carrier mutations refer to individuals who possess one copy of a mutated gene and can pass it to their children, again involving both parents. Chromosomal mutations affect the structure or number of chromosomes and can also be inherited from either parent. Thus, the most distinctive attribute of mitochondrial mutations is their exclusive maternal inheritance, making them the correct answer in this context.