Mendel's results allowed the development of a hypothesis.

1. Each trait (seed color) is determined by a pair discrete of physical units (he called them Elemente and we now call genes. One from each parent.

2. Alternative versions of genes (different alleles )account for variations in inherited characters.

3. If two alleles differ then one, the dominant allele is fully expressed in the organisms appearance; the other, the recessive allele, has no noticeable effect on the organism's appearance.

4. The pairs of genes separate during gamete formation (Meiosis) so that the offspring receives only one of each parents pair of genes. Law of segregation

MonoHybrid Crosses: a cross involving one trait                         More Experiment: Crossing a homozygous purple flowered plant with a homozygous white flowered plant
Appearance = phenotype Genetic make-up = genotype   F1 = a hybrid formed by crossing differing pure-breeding parents.       F2 = the offspring produced by inbreeding the F1.     Homozygous = both alleles the same. Hetrozygous = both alleles the different. More >>

Punnet squares are used to show the different kinds of fertilization events.

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Key terms:

Basic facts: http://homepages.ius.edu/GKIRCHNE/biomolec.htm