Characteristics that are inheritable are passed on through our genes. We get 50% of our genes from the father, 50% of the genes from the mother so, depending whether it’s the sperm donor or egg donor that you’re using, the baby will have 50% of the characteristics of the donor and the other 50% from the intended parents whose gametes we have used but of course genes are not just from the mother and the father, they go back to your ancestry so the grandparents and the grand grandparents genes will also be included in the pool of genes that the embryo or the baby will receive and therefore, sometimes, characteristics can go back to even further to grandparents or great-grandparents.
The answer is no. Genetics is modeled by something we call epigenetics. While genetics is in charge of what kind of characteristics or information could pass through the generations. Epigenetics module them in order to dictate when and where the information contained in the genes are translated. Epigenetics also is part of the environment. Epigenetics and the environment can be responsible for the differences between identical twins, for example. In that way, a certain amount of features are inheritable but some others are not. The environment can change those features because they are affected by the conditions surrounding the person.
