1. Chapter 5 Basic Genetics GCA General Biology Mr. Cobb

2. Mendel’s Genetics Monk Worked with pea plants 7 traits

3. Mendel’s Concepts Unit Characteristics Dominant and Recessive Law of segregation

4. Unit Characteristics Traits are caused by factors that occur in pairs. He represented these with letters. T = tall t = short

5. Dominant & Recessive Dominant gene hides a recessive gene. TT = Tall plant Tt = Tall plant tt = short plant

6. Segregation What does Segregate mean? When a cell forms gametes genes separate. Only 1 factor for each trait will be in each gamete. He had figured out Meiosis, but did not know why or how.

7. Terminology Phenotype = physical appearance Genotype = the specific genes allele = an alternate form of a gene (purple flower allele or white flower allele) Homozygous = both alleles are the same Heterozygous = alleles for a trait are different.

8. Punnett Squares Use to determine the probability of an outcome. 25% both heads 50% heterozygous 25% both tails

9. Punnett Square Free earlobes = F Attached = f What is phenotype and genotype?

10. Punnett Square Results are expressed in ratios pg. 116 homozygous dominant: heterozygous: recessive. Cross two heterozygous for trait P, what is the genotypic ratio. P is for purple and p is for yellow, what is the phenotypic ratio?

11. Test Cross If you corn that shows the dominant purple kernels (P), then what is the genotype? PP or Pp, it could be either. Do a test cross and mate with corn that is yellow recessive because that genotype is pp. If any of the offspring show the recessive trait, then the unknown was heterozygous.

12. Variations of Mendel Incomplete dominance = one trait is not completely dominant over the other, so they “blend”. Red flower + White flower = pink

13. Variation (continued) codominance = both alleles are expressed, but there is no blending.

14. Variation (continued) Multiple alleles = More than two alleles in the population. Blood type

15. Blood Type A and B Blood Types are both Dominant and notated by I A and I B. The recessive is not having the antigens and it is notated as i. A person with A blood type could be I A I A or I A i AB Blood type is I A I B. Read the box on top of page 121. Did a mixup happen?

16. Dihybrid Crosses Same as Punnett Square, but now we are looking at the probability of two traits together Our example is pod color and is the pod constricted (skinny) or inflated (fatter).

18. Dihybrid Cross When would this be useful in society?

19. Independent Assortment The separation of one allele does not affect the other alleles. For example, the pod color does not affect the pod shape or flower color. These alleles are sorted independently of each other.

20. Independent Assortment The “G” Chromosome is independent from the “I” chromosome.

21. Polygenic Inheritance 2 or more genes working together result in a single trait. Human traits like hair color, skin color, eye color, height. The example in the book is the comb of chickens.

22. Pleiotrophy Just FYI Pleiotrophy is one gene controls many characterisitics. Example is sickle cell anemia and affects 1 in 12 black people in the U.S. Sickle cell anemia causes the red blood cell to sickle in high elevation and in activity.

23. Sickle Cell Anemia Ryan Clark of Pittsburgh can not play in Denver due to sickle Cell Anemia. Sickle Cell Anemia Red Blood Cells

24. Sex Chromosomes Chromosomes that determine the sex of an individual. The autosomes are the other 22 chromosomes. XX is a female XY is a male

25. Sex Chromosomes The male donates the Y chromosome. So the male determines the sex of the offspring.

26. Sex Chromosomes There are traits on the chromosomes and these are called sex-linked traits. Hemophilia - blood does not clot correctly baldness color blindness

27. Sex Chromosomes Males usually exhibit the traits. Why? Males only have 1 X chromosome and females have 2 X chromosomes. Males will exhibit the recessive trait.

28. Color Blind Test

31. Pedigree A chart used to track a genetic trait through a generations. This is a pedigree of hemophilia in the British Royal Family.