What is simple recessive heredity? ?

Recessive heredity refers to the mode of inheritance in which a particular gene is ped through the generations. If the parents are heterozygous for a particular trait (Aa) then they carry the recessive allele which joins with the allele of the father (pretend AA zygous dominant) so their child can be AA or Aa. The allele gets ped down, and if the child has Aa and marries someone with Aa, they have a chance (25% chance) of having a child 'aa' who would express the recessive allele in their phenotype.