Mendel was not the first to propose genetics however, he was the first to figure out that genes (he called them elements) came in pairs and that one member of each pair came from each parent. As a result of his realization regarding pairs of genes, Mendel determined what are called Mendel's laws of inheritance..
Chickens usually don't simply stop laying eggs when they get to a certain age, but they will lay fewer as they get older.That said, most laying breeds will lay more or less productively in backyard terms for five or seven years.hickens usually don't simply stop laying eggs when they get to a certain age, but they will lay fewer as they get older.
Tipically, a well fed chicken, with proper living conditions and from a good breed (such as Isa Brown) should start laying eggs at week 19 or 20. It will reach its peak of production between week 25 and 30, then it will decline but the bird will keep laying eggs until a very old age.