Symbiosis
During mutualistic symbioses, the host cell lacks some of the nutrients, which are provided by the endosymbiont. As a result, the host favors endosymbiont's growth processes within itself by producing some specialized cells. These cells affect the genetic composition of the host in order to regulate the increasing population of the endosymbionts and ensuring that these genetic changes are passed onto the offspring via vertical transmission (heredity).
What does the host make that affect its genes?
specialized cells
As a result, the host favors endosymbiont's growth processes within itself by producing some specialized cells.
the host