Lecture 1.2 Laws of inheritance established by Gregor Mendel

Lecture 1.1 The subject and the main tasks of genetics. Milestones of genetics

1. Subject of genetics

2. Basic concepts of genetics

3. Place of genetics among the biological sciences

4. History of Genetics

5. Problems and prospects of genetics as a biological science

Lecture 1.2 Laws of inheritance established by Gregor Mendel

Plan

1. An ideal experimental organism characteristics

2. The features examined by Gregor Mendel

3. The laws of Gregor Mendel: hybrids uniformity in the first generation (dominance law), the law of segregation, the law of features independent assortment

4. Standard phenotype classes numerical ratios in the segregation and deviations from it

Table Model Experimental Organisms

Species Name Common Name Some Research Uses

Escherichia coli E. coli Bacterial genetics

Drosophila Fruit fly Development, molecular genetics,

melanogaster genome structure, transgenics

Mus muscalis Mouse Mammalian development,

gene regulation

Arabidopsis thalania Wall cress Plant development

Caenorhabditis elegans Roundworm Animal development

Figure The Seven Traits that Mendel Studied in Pisum Sativum

(Courtesy of Ricochet Productions)

Figure 1.3 Mendel’s Single-Trait Crosses

(Courtesy of Ricochet Productions)

Mendel’s Experiments with Two-Trait (Dihybrid Crosses)

(Courtesy of Ricochet Productions)

Number of hybrids classes by phenotype and genotype and the character of splitting in F₂ with a different number of traits pairs (complete dominance)