Different Patterns of Inheritance

1. Different Patterns of Inheritance Intermediate, Codominant, And Polygenic

2. Variations of Inheritance • Intermediate Inheritance • Codominance (multiple alleles) • Polygenic Inheritance

3. Intermediate Inheritance • No “dominant” allele • Heterozygous organism has completely different phenotype Andalusian Chickens Blackmale + White female = Blue baby chick How is this different from what we already know?... Neither black or white is dominant over the other

4. Intermediate Inheritance

5. Intermediate Inheritance • Not the “blending hypothesis” !! • Parent phenotypes can reappear in later generations • cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blendingof the parental traits.

6. Intermediate Crossing Tips! Notice!! Different Letters but still a MONOHYBRID cross! • The trick is to recognize when you are dealing with a question involving incomplete dominance. There are two steps to this: • 1) Notice that the offspring is showing a 3rd phenotype • 2) Notice that the trait in the offspring is a blend (mixing) of the parental traits.

7. Codominance • Multiple Alleles = codominance • The heterozygous expresses BOTH traits together • Different from intermediate (blends) Cattle can be red(RR = all red hairs), white (WW = all white hairs), or roan(RW = red & white hairs together) Aww.. he has your eyes Whatever… Genetics rules

8. Blood Types O+ Most frequent AB- Least

9. Blood Types • The A antigen, you have type A blood. • The liquid portion of your blood (plasma) has antibodies that fight against type B blood. In the United States, about 40% of the white population, 27% of African Americans, 28% of Asians, and 16% of Native Americans are type A. • The B antigen, you have type B blood. • Your plasma has antibodies that fight against type A blood. In the U.S., about 11% of the white population, 20% of African Americans, 27% of Asians, and 4% of Native Americans are type B. • Neither the A nor B antigen, you have type O blood. • Your plasma has antibodies that fight against both type A and type B blood. In the U.S., about 45% of the white population, 49% of African Americans, 40% of Asians, and 79% of Native Americans are type O. • Both the A and B antigens, you have type AB blood. • Your plasma does not have antibodies against type A or type B blood. In the U.S., about 4% of the white population, 4% of African Americans, 5% of Asians, and less than 1% of Native Americans are type AB.

10. Blood Types • Type O-negative blooddoes not have any antigens. • It is called the "universal donor" type because it is compatible with any blood type. • Type AB-positive bloodis called the"universal recipient"type because a person who has it can receive blood of any type. .

11. Blood Typing! Danny is type AB Bianna is type A What are their genotypes? What are their possible offspring’s blood types?

12. Blood Typing! Kristina is type B but her mother was type O Kyle is type A but his father was type O What are Kristina and Kyle’s genotypes? Is it possible for their child to be type O?

13. Difference b/w Intermediate and Codominance • With intermediate, get a blending of the dominant & recessive traits so that the third phenotype is something in the middle (red + white = pink). • In Codominance, the "recessive" & "dominant" traits appear together in the phenotype of hybrid organisms.

14. Or the easy way… • Intermediate • (red + white = pink). • Codominant • Red + White = Red and white spotted

15. Practice, Practice, PRACTICE! A red-flowered sweet pea plant is crossed with a white-flowered sweet pea plant. All of the offspring are pink. What is the inheritance pattern being expressed? If roan cows and roan bulls are mated, according to the principle of codominance, ______% of the offspring are expected to be roan.

16. Polygenics • Multiple GENES affect the traits being expressed • Skin color • Hair color • Eye color

17. How it works… Eye Color = Brown Eye Color = Hazel Skin Color = Light Skin Color = Tan

18. Eye Color

19. QUICK FIRE • 1. Explain the difference (and use an example) between intermediate and codominance. • 2. What is polygenics? • 3.Blood type is an example of what type of variation in inheritance • 4. How many phenotypes are visible in intermediate inheritance? Codominance?

20. Experiment

21. Sex Linked Traits • Sex Chromosomes (X, Y) • In humans male determined sex of offspring • Give X = female • Give y= male • Genes can be located on sex chromosomes = Sex Linked Traits • Mostly on X for humans Discovered by Thomas Morgan when experimenting with fruit fly eye color

22. Fruit Fly Eyes…Oh my • Normally fruit flies have red eyes • Notice some had white • But none of them female!! • Figured out that the trait for eye color (red) is located only on the X chromosome • Explains why males are white eyed Red is dominant to White

23. Fly Experiment • Eye color carried on X • R = red r = white • More males are white than female be cause Male XY Female XX

24. Sex Linked Disease Females can be carriers, males will show it • Red- green color blindness • Night Blindness • Fragile X syndrome • Sickle Cell Anemia • Huntington's disease • Hemophilia MOST sex linked recessive

25. Sex-Linked Genetic Cross No Traits carried on “Y” This is why MALES usually show the recessive trait!!

26. Triple P Time!! Practice Problem Packet!! You are now ready to complete the BOLD questions…