Question

what are the odds that a grandmother will donate her mitochondrial dna to a future grandson? 0 1 in 2 1 in 4 1 in 8 1 in 16

Explanation:

Step1: Understand mitochondrial DNA inheritance

Mitochondrial DNA is maternally inherited. A grandmother passes her mitochondrial DNA to her daughters. Her sons do not pass on her mitochondrial DNA.

Step2: Analyze the path to a grandson

For a grandmother to donate mitochondrial DNA to a grandson, the grandson must come through her daughter (so that the mitochondrial DNA is passed from grandmother to daughter to grandson). If the grandson is through her son, since sons do not pass on maternal (grandmother's) mitochondrial DNA, there is no transfer. But if we consider all possible grandsons (assuming equal chance of sons and daughters for each child - which is a simplification for the sake of this problem), but in reality, when looking at the mechanism of mitochondrial DNA inheritance: Sons cannot pass on their mother's (grandmother's) mitochondrial DNA. So the probability that a grandmother donates mitochondrial DNA to a grandson is \(0\).

Answer:

0