* Embryo: The embryo receives half of its genetic material (DNA) from the father through the sperm and half from the mother through the egg.
* Host Mother: The host mother provides the environment for the embryo to grow, but her own genetic contribution is limited to the egg cell. This egg cell contains only half of her genetic material.
Therefore, the embryo shares 50% of its genetic material with the host mother, the same percentage shared by full siblings. This makes their relationship akin to half-siblings.
It's important to note that this is true for biological pregnancies. In cases of surrogacy or adoption, the genetic relationship between the child and the host mother can be entirely different.
