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Thus relatives share similar DNA. The average percentage they share is clear, but without further knowledge of their DNA (genotypes) or their phenotypes, it is not clear which part of the DNA, which alleles they share.
2.7.1 mt- and Y-DNA
The mitochondria in the cells descend from the mitochondria in the oocyte of the mother. They contain DNA and form a maternal extra-nuclear inheritance. This DNA is called mt-DNA and can be used to trace female genetic lines in pedigrees.
They Y-chromosome is only passed from father to son. The DNA on this chromosome is called Y-DNA, it shows no crossing over and can be used to trace male genetic lines in pedigrees.