Final answer:
The coefficient of relationship between a human individual and one of its grandparents is 0.25, meaning an individual shares 25% of their genetic material with one grandparent.
Step-by-step explanation:
The coefficient of relationship, which is the probability of identity by descent, measures how much genetic material is shared between relatives. For a human individual to one of its grandparents, this coefficient is 0.25 (or 25%).
Each parent carries two sets of genetic material, one of which is passed down to their children. A person inherits 50% (0.5) of their genetic material from each parent. Each parent, in turn, inherited 50% of their genetic material from each of their parents. Thus, an individual inherits 25% (the product of 0.5 x 0.5) of their genetic material from each grandparent. Therefore, the coefficient of relationship to one grandparent is 0.25, representing the shared genetic material between the grandchild and the grandparent.