DEXTER GICARO BALBOA
UNO-R
Coverage of this Lecture
• Mendelian Genetics
• Extension of Mendel’s Laws
• Problem Sets
Mendelian Genetics
•
Also known as
Transmission Genetics
•
Explores how the genetic material is inherited from generation to generation Mendelian Genetics
The first significant insights into the mechanisms involved in inheritance occurred in 1866 with the works of Gregor Johann
Mendel
His publication lay the foundation for the formal discipline of genetics
Father of Modern Genetics
Mendelian Genetics
• Mendel has been credited with discovering the first two laws of inheritance:
Law of Segregation: o unit factors for the same character segregate independently from one another during the formation of gametes o During meiosis, homologous chromosomes pairs segregate/ separate from each other independently of one another toward the opposite poles of the cell to form progeny cells of different chromosome combinations
Mendelian Genetics
• Mendel has been credited with discovering the first two laws of inheritance:
Law of Independent Assortment: o “the behavior of each pair of differing traits in a hybrid association is independent of all other differences in the two parental strand” o During the course of segregation of alleles different genes assort/ combine indefinitely and independently with other alleles of other genes o Exception “Linked Genes”
Reviews on Mendel’s Paper: Mendel is not a Mendelian
About speciation and hybridization
He tried to find a generally applicable law governing the formation and development of hybrids
Mendel never mentioned the now-famous 9:3:3:1 ratio in his paper
Do not announced any major discoveries or laws
Do not introduce the concept of equivalence
Do not study the inheritance of characters
Mendel’s work went unnoticed until 1900s, but in the ensuing years the concept of the gene as a distinct hereditary unit was established The ways in which genes, as members