1. Ch12: Early genetics and Mendel
Advanced Biology
Chapter 12

2. Research done by such people as Josef Koelreuter and T.A. Knight
Early Genetics
Research done by such people as Josef Koelreuter and T.A. Knight
Hybridizations - the mating of unlike parents to produce an offspring

3. Early Genetics
Segregation - after mating, traits segregate to either offspring. Some offspring show same trait as parent, some show different traits

4. True-Breeding - Varieties are uniform from generation to generation.
Early Genetics
True-Breeding - Varieties are uniform from generation to generation.

5. picked up where Knight left off, testing garden pea plants
Mendel’s Work
picked up where Knight left off, testing garden pea plants

6. Mendel’s Work Two ways to produce offspring Self-fertilization
Or by doing an experimental cross-
pollinate a plant using pollen from a different plant with alternative characteristics

7. Mendel’s Work
Monohybrid cross: a cross to study only 2 variations of a single trait
Mendel produced true-breeding pea strains for 7 different traits
-each trait had 2 alternate forms (variations)
-Mendel cross-fertilized the 2 true-breeding strains for each trait

8. What exactly did Mendel do?
1st- allowed plants to self-fertilize for many generations to ensure that each trait would be constant for each generation
2nd- Crossed purple plants with white plants
3rd- Allowed those plants to self-pollinate and record the results

11. What did Mendel find?
Hybrid- The resulting generation from two different parents
First Filial Generation F1 - Contains the hybrid generation - in Mendel’ case, all the flowers were purple.

12. What did Mendel find?
Dominant Trait - the trait that is expressed - purple flowers
Recessive Trait - the trait that is masked or not expressed

13. What did Mendel find?
Second Filial Generation F2 - Contained the recessive trait not exhibited in the F1 - white flowers
Mendelain Ratio - 3 parts dominant to 1 part recessive

14. 1) Parents transmit information in the form of genes
Mendel’s model: 5 parts
1) Parents transmit information in the form of genes

15. Mendel’s model: 5 parts
2) Each human contains two factors for a specific trait. These factors may code for the same form of the trait or code for an alternative form of that trait.(Diploid). During Meiosis, the forming of a haploid gamete, only one factor for each trait is included in the genome and that is random

16. 3) Alleles - two of the same alleles = homozygous
Mendel’s model: 5 parts
3) Alleles - two of the same alleles = homozygous
two different alleles = heterozygous

17. Mendel’s model: 5 parts
4) Alleles are independent of each other. The only difference is which one is “turned on”

18. Mendel’s model: 5 parts
5) All genes are not expressed. Some are turned on and some are turned off. All the alleles an individual has is called genotype. The physical characteristics exhibited by an individual is called phenotype.

19. Mendel’s model: 5 parts
Punnet Squares and the Test Cross (pg 240) - to test his work, Mendel used a punnet square to figure out how the alleles segregated.

22. Mendel’s Laws of Heredity
Mendel’s first law of segregation - alleles segregate randomly
Dihybrid – heterozygous for two genes

23. Mendel’s Laws of Heredity
Mendel’s second law of Independent Assortment – genes on different chromosomes assort independently during meiosis