Q: Do you inherit everything from your parents? What does gene mean?
A: At the moment of fertilization there is a transmission of genetic codes of both parents and with this, the genetic endowment is well defined.
A person has 46 chromosomes, but the egg and the sperm only have 23 each. When they join, they add up to 46 and in an equal proportion, you have 23 from each parent.
Genes are chemical substances that are in charge of defining in detail each one of the characteristics of each person: the color of skin, number of fingers, inner and external organs.
It could happen that the color of eyes, hair, height, and physical traits are transmitted in a way that the child looks just like one of the parents. This happens thanks to the union of chromosomes within the nucleus of the cells containing the genes with all the necessary information for the development and functions of a new human being.
Each person is unique and genuine. There is only one exception that happens with identical twins, in which case the genes are exactly the same.
Genes are distributed in an equal way, but sometimes some are dominant over the others, thus imposing their genetic load. For instance, if the genes of the father who has green eyes dominate, the child will have green eyes even if the mother´s are blue. In the same way some of the genes of the mother dominate so that the child has some other traits, such as the color of skin or hair. Some other times, the father´s genes dominate, such as in the form and size of the eyes, nose, etc.
It could also happen, however, that both genes dominate, and the child has a mixture of both, sometimes with green-blue eyes or some other combinations. And it could also be that the child has a completely different color.
There are sicknesses genetically transmitted, or in a hereditary form if the gene that has the genetic code for that particular sickness is in the egg or sperm, then the child might develop the sickness, and will transmit it from one generation to the next.
This can be better studied and understood when consulting the genetic laws of Mendel, which indicate more precisely the distribution of the genetic inheritance from parents to children.