Question

If two people have the same mtDNA, what can you infer about their biological relationship?

Answer 1

They are related mother to child. mtDNA is DNA contained in the mitochondria, and does not change from mother to child. So, it could be a grandma and her grandchild if she had a daughter, or a mother and her child.

Answer 2

Mother and her child or grandmother and her grandchild.

Step-by-step explanation:

The mt DNA is the extra chromosomal DNA. They sometimes inherited to the offspring. The mt DNA passes only from mother to child. Because the mother's egg and sperm DNA take part in fertilisation. The sperm mt DNA destroys in the enzymatic action of the egg. Therefore, only maternal mt DNA is transmitted to the next generation, not the paternal mt DNA. mt DNA is helpful to know the phylogeny of animals. If two people have the same mt DNA, the relation between them is a mother and her son/daughter or grandmother and her grandson/granddaughter.