We’ve just explored Mendel’s laws of inheritance, and learned many vocabulary terms. Alternative forms of a gene are called alleles, which can be dominant or recessive. A genotype is the allelic makeup of an organism. Organisms are heterozygous when they have two different alleles, and homozygous when they have identical alleles. A phenotype is the physical translation of a genotype.

Mendel’s experimental method was a carefully planned and carried out scientific process. He gathered data on thousands of plants!

Mendel’s law of segregation states that allele pairs separate during gamete formation and then randomly unite when gametes fuse during fertilization. His law of independent assortment states that each allele pair segregates independently during gamete formation.

A Punnet square can be used to predict the types and ratios of offspring for monohybrid and dihybrid crosses.

Mendel’s laws of inheritance apply to all diploid organisms, including humans. Both PTC bitterness and earlobe attachment are inherited in a Mendelian fashion. The inheritance of some other human traits is more complex. But such patterns still depend on the fundamental genetic groundwork performed by Mendel.

Copyright 2006 The Regents of the University of California and Monterey Institute for Technology and Education