A parent is either the progenitor of an offspring, or in humans, it can refer to a caregiver or legal guardian, generally called an adoptive parent or step-parent. Parents are first-degree relatives and share 50% of their genes. A female can also become a parent through surrogacy. Some parents may be adoptive parents, who nurture and raise an offspring, but are not related to the child. Orphans without adoptive parents can be raised by their grandparents or other family members.