Although man has been engaged in breeding domestic animals and plants since prehistoric times, a real understanding of these concepts was first gained during the years 1856-1868. During this time the Austrian monk, Gregor Mendel performed some extraordinary experiments with the common garden pea. The results of these experiments, published in 1866, initiated a whole new science called genetics. This is the mechanism which ensures that the chromosome number is reduced. Be sure you know what we mean when we speak of homologous chromosomes.
Homologous chromosomes have genes for the same trait at the same point along their length.
In animal sexual reproduction one chromosome was contributed by the sperm, and one by the egg within each homologous pair. This separation of the chromosomes during gamete formation is what is termed The Law of Segregation or Mendel's first Law. Evidence of this law is provided and explained by the monohybrid and test cross. I of meiosis three homologous pairs can separate in any one of eight different combinations. Lab Index Page Go Forward to Next Page Go to the University of Manitoba UM info home page.