1. Fundamentals of Genetics
Modern Biology, Holt, Rinehart & Winston © 2009 pp

2. Mendel’s Legacy Gregor Johann Mendel: 1822-1884
1843: Monastery in Brunn, Austria; assigned to gardens
1851: University of Vienna; studied science & math/ statistics
Experimented with garden peas, Pisum sativum, et al
True-breeding plants
Offspring always has parents’ trait when plants self-pollinate
Self-pollination
Same flower or flowers on the same plant; pollen from anthers to stigma’s eggs
Cross-pollination
Removed anthers/ pollen from receiving plants 1st

3. Parts of a Flower

5. True-breeding Traits

9. Probability Probability = # of times an event is expected to occur
# of times an event could happen
Percent probability = probability x 100%

11. Genetic Crosses Complete Dominance Incomplete Dominance Codominance
The dominant trait is expressed if the dominant allele is present
Red + White  Red
Incomplete Dominance
The phenotype is a merge of the dominant & recessive alleles
Red + White  Pink
Codominance
The phenotype is a mix of both alleles
Red + White  Red & White polka-dots, stripes, patches, etc…

13. Complete Dominance

14. Incomplete Dominance

18. Sex-linked Disease: Hemophilia

20. Autosomal dominant: Huntington’s disease