The seven phenotypic pairs studied by Mendel
Established Pure lines of each
Q: If you were Mendel, and you could only study one trait which would like to study?
A. Round vs. wrinkled → individual, can tell right away
B. Purple vs. white flowers
C. Long vs. short
D. Green vs. yellow pods: part of female genetic makeup - “womb”
Cross-pollination and selfing are two types of crosses
→ At the time:blendingwas predominant theory
- no blending
- yellow dominant 6022
2001 Mendel’s First Law: Law of equal segregation
From a monohybrid cross, each parent has an equal chance of contributing one of the two factors.
→ Monohybrid= heterozygous for one trait.
Amonohybrid cross is a cross between parents who are heterozygous.
Ratios from single gene inheritance:
• Experiments in Plant Hybridization (1865) by Gregor Mendel
• Proceedings of the Natural History Society of Brünn (Original title in German: Verhandlungen
des naturforschenden Vereins Brünn)
… meanwhile 34 Years later: Chromosome theory of inheritance
Chromosome Theory: Chromosomes (“coloured bodies”) , which are seen in all dividing cells and
pass from one generation to the next, are the basis for all genetic inheritance
The nuclear genome
Indian muntjac only has 6 chromosomes: 2n =6 Chromosomal DNAis wrapped around histones (proteins)
Representative chromosomal landscapes