Question

Which of the following best describes the pattern of inheritance for mitochondrial DNA?

1) Autosomal dominant inheritance
2) Autosomal recessive inheritance
3) X-linked dominant inheritance
4) Maternal inheritance

Answer 1

The pattern of inheritance for mitochondrial DNA is maternal inheritance(option 4), meaning traits encoded by mitochondrial DNA are passed from mothers to all of their offspring, but only daughters pass these traits on to the next generation.

Step-by-step explanation:

The pattern of inheritance for mitochondrial DNA is maternal inheritance. This is because mitochondria, the organelles that contain their own DNA and are responsible for producing the energy required by cells, are inherited exclusively from the mother.

This is in contrast to autosomal inheritance (either dominant or recessive), which involves genes on the 22 non-sex chromosomes, or sex-linked inheritance, which typically involves genes on the X chromosome. In maternal inheritance, all of an individual's mitochondria are usually inherited from the egg provided by the mother, as the mitochondria from the sperm are typically destroyed after fertilization.

Therefore, mitochondrial conditions are passed down from mothers to all their children, but only daughters can pass on the mitochondrial traits to the next generation.

Since mitochondrial DNA does not follow autosomal dominant, autosomal recessive, or X-linked patterns of inheritance, the correct option to describe the pattern of inheritance for mitochondrial DNA is maternal inheritance.