How do you and your partner’s genes determine what attributes your baby will inherit?
We inherit aspects of temperament and physical appearance from our parents. Each type of gene occurs in pairs, and each pair that we inherit contains one gene from our mother and one gene from our father. Our genes determine every factor of our being including eye and hair colour, personality, facial features, sporting ability, intelligence and resistance to diseases among many other things.
In an inherited pair of genes a dominant gene will overpower a recessive gene. For example, brown eyes dominate over blue in four out of five occurrences.
Recessive genes can pass through several generations before they reappear as shown with the gene that makes hair red. This is because the brown-hair gene dominates the red-hair gene.
Generations of two families of brown-haired people can unknowingly hand on a red-haired gene. Only when an individual inherits two of these recessive genes will that person have red hair. Therefore, it is possible that a child resembles its grandparents or great-grandparents more than its parents.