1. Genetics

2. I. Mendelian A. Introduction 1. History
a. C. Darwin & A. Wallace proposed blending
b. In 1860, G. Mendel & F. Unger proposed mixing

3. B. Experimental Design 1. Monohybrid Cross a. Definition b. Terms
i. Self vs. Cross Fertilization
ii. Traits vs. Characteristics

4. c. Process
Figure 10.1
Figure 10.2

5. i. Outcomes for a one trait cross or a Monohybrid cross
ii. Principle  All traits are paired and sorted into gametes
Figure 10.3

6. ii. Homozygous versus Heterozygous
d. Terms
i. Gene versus Allele
ii. Homozygous versus Heterozygous
iii. Dominance versus Recessive
iv. Genotype versus Phenotype
e. Testcross
What are the parental genotypes?
Figure 10.4

7. 2. Dihybrid Cross a. Definition b. Process
Always start these crossing questions by figuring out the parents and then how many and what type of gametes are produced.
Figure 10.6

8. i. Outcomes
AaBb X AaBb
Dihybrid Heterozygous cross
Both Parents are AaBb
Gametes = AB, Ab, aB, & ab for both parents
Phenotypic ratio= 9:3:3:1 & Genotypic ratio= 1:1:2:2:4:2:2:1:1
Dihybrid Heterozygous cross with a Homozygous Dominant
Parents are AaBb X AABB
Gametes AaBb = AB, Ab, aB, & ab; AABB= AB only
Phenotypic ratio = all dominant, Genotypic ratio = 1:1:1:1
ii. Principle  Each pair of alleles and chromosomes sort independently into gametes.

9. II. Variation on Mendel A. Incomplete Dominance
Appears to be a blending of the two alleles vs. complete dominant.
Figure 10.6

10. B. Co-Dominance AA aa Aa
Expression of alleles yields both traits in heterozygote.

11. C. Multiple Alleles
Figure 10.17
Multiple alleles are needed to give the expression of the trait.

12. D. Penetrance
The timing of expression of traits in the phenotype.

13. E. Gene Interactions 1. Pleitrophy 2. Polygenic
Figure 10.18
Figure 10.21
One gene causing many different effects
Continuous Variation of Expression of traits

14. 3. Epistasis Interference of expression between different genes
Just to make sure you can tell the difference.

15. III. Classical Genetics
A. History
1. W. Bateson & R. Punnett (1908) Punnett Square

16. 2. T. Morgan (early 1900’s) used fruit flies WHY?
Recombination experiments
a. Developed karyotyping techniques,
Figure 13.7

17. b. Discovered linkage group studies,
Figure 9.4

18. & c. sex linkage studies.
Figure 10.24

19. 3. A. Sturtevant
a. Gene mapping
Based on frequency of expression between differen genes

20. IV. Detection of Problems
A. Karyotyping
How?
B. Amniocentesis  Cellular and Chemical Analysis
Figure 13.8

21. C. Ultrasound gives a sound (visual) image of the fetus.
D. Chorionic Villi Sampling== placenta samples

22. E. Fetal Tissue Sampling

23. F. Pedigrees == familial history
Figure 10.9
Figure 10.10

24. Figure 10.25