Lab 15: Population Genetics - eScience Labs

Lab 14: Mendelian Genetics
Concepts to explore:
Gregor Mendel
Law of segregation
Homozygous
Heterozygous
Independent assortment
Dominant vs. recessive
Incomplete dominance
Co‐dominance
Genotype
Phenotype
Monohybrid cross
Dihybrid cross
Punnett square
Introduction
In 1866, Gregor Mendel, an Austrian Monk, published a paper entitled “Experiments in plant hybridization”.
It went largely unnoticed until 1900 when it was rediscovered and subsequently became the
basis for what we now refer to as Mendelian Genetics.
Mendel was the first to recognize:
Inherited characters are determined by specific factors (now recognized these as genes).
These factors occur in pairs (genes).
When both alleles of a gene are the same they are said to be homozygous, while if they are different
they are said to be heterozygous. When gametes form, these factors segregate so that each gamete
contains only one allele for each gene. Remember, alleles reside on the chromosomes that are dividing.
These original observations lead to what we now refer to as The law of segregation and the law of
independent assortment.
Figure 1: Law of Segregation
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