The genes are from the nuclei of the egg (from the female) and the sperm (from the male) the different traits are joined to create the particular genes.
(I might be right.)
An example of a parasite would be a worm in your intestine
Reproductive isolation. Species refer to the group of organisms which share common morphological features and can interbreed and produce a viable offspring. Thus, the organisms of one species are reproductively isolated from the organisms of other species
