Patterns of InheritanceChapter 10
Gregor Mendel
• Austrian Monk (1800’s)
• Mathematician
• Heritable factors
• Peas
Mendel’s 4 Theories
• Alternate forms of genes exist (Alleles)
• 2 genes per trait
• Gamete only carries one allele
• Dominance vs. Recessive
Mendel Got Lucky
• Incomplete Dominance
• Multiple Alleles
• Pleiotropy
• Polygenic inheritance
• Linkage
Incomplete Dominance
RR Rr rr
Polygenic Inheritance
Other Info• Chromosomes determine sex in many species,
not just humans
• Sex chromosomes carry other genes– Sex linked– Some diseases have sex linkage component