Grandparent
Grandparents, individually known as grandmother and grandfather, or Grandma and Grandpa, are the parents of a person's father or mother – paternal or maternal. Every sexually reproducing living organism who is not a genetic chimera has a maximum of 4 genetic grandparents, 8 genetic great-grandparents, 16 genetic great-great-grandparents, 32 genetic great-great-great-grandparents, 64 genetic great-great-great-great-grandparents, etc.