1. Chapter 6
Genetics of Organisms

2. The Origin of Modern Genetics
Chapter 6A
The Origin of Modern Genetics

3. I. Genetic Vocabulary

4. The study of the inheritance of traits
Genetics
The study of the inheritance of traits

5. The passing of traits from parents to offspring
Inheritance
The passing of traits from parents to offspring

6. Mating organisms to test how they inherit traits
Cross
Mating organisms to test how they inherit traits

7. Alleles
The different forms of the gene for a particular trait (Mendel called them factors)

8. The physical way a plant or organism looks
Phenotype
The physical way a plant or organism looks

9. The specific factors (genes) an organism contains
Genotype
The specific factors (genes) an organism contains

10. II. Gregor Mendel The man Father of Modern Genetics Monk in Austria
Worked with pea plants
Wrote paper about his experiments

11. II. Gregor Mendel
B. His Experiments 1. Cross pollinate plants

12. 1. Pollen-containing structures are removed from short-plant flowers.
2. Tall-plant pollen is collected using a brush.
3. Tall-plant pollen is placed onto stigmas of short-plant flowers.

13. Mendel’s Experiments
tall +
short =
tall
???

14. F1—1st Filial Generation
Mendel’s Experiments
F1—1st Filial Generation

15. Mendel’s Experiments
F2 Generation

16. B. His Experiments

17. II. Gregor Mendel
C. His Theories 1. If an organism’s two alleles (Mendel used the word factors) for a trait are the same, the organism is purebred for that trait.

18. II. Gregor Mendel
C. His Theories 2. If an organism’s two alleles (factors) for a trait are different, the organism is hybrid for that trait.

19. II. Gregor Mendel
C. His Theories 3. Each allele (factor) in a set of two alleles for a trait is either dominant or recessive.

20. II. Gregor Mendel
C. His Theories 4. When there is one of each, the dominant trait will be shown.

21. B. His Experiments
D. His Notations 1. Dominant alleles are represented with capital letters. 2. Recessive alleles are represented with lowercase letters.

22. B. His Experiments
D. His Notations 3. All diploid organisms have two letters to represent their genotype for a particular trait.

23. TT x tt
Tt (F1)

24. Tt x Tt TT Tt Tt tt

26. III. Post Mendel’s Experiments
Mendel’s work went unnoticed for over 35 years
In the mid-1900s scientists described the DNA molecule and realized that Mendel’s factors were actually genes.