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Today we are going to learn about… Multiple Alleles and Polygenetic

Today we are going to learn about… Multiple Alleles and Polygenetic. In a nutshell!. http://www.athro.com/evo/inherit.html. Brainteaser.

phailin-suttikul
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Today we are going to learn about… Multiple Alleles and Polygenetic

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  1. Today we are going to learn about…Multiple AllelesandPolygenetic In a nutshell! http://www.athro.com/evo/inherit.html

  2. Brainteaser • While on Safari in the wild jungles of Africa, Professor Claudia woke one morning and felt something in the pocket of her pajamas. It had a head and a tail, but no legs. When Claudia got up she could feel it move inside of her pocket. However, Claudia showed little concern and went about her morning activities. Why wasn't she concerned?

  3. Let’s Review • What is incomplete dominance? • What is genotype? • What is heterozygous? • What is phenotype?

  4. A cross between a blue blahblah bird & a white blahblah bird produces offspring that are silver.  • What are the genotypes of the parent blahblah birds in the original cross? • What is/are the genotype(s) of the silver offspring? • What would be the phenotypic ratios of offspring produced by two silver blahblah birds?

  5. Multiple Alleles • There are more than _2_alleles for a trait • Blood type in humans • Blood Types? • Type A, Type B, Type AB, Type O • Blood Alleles? • A, B, O (in book – IA, IB, i)

  6. Rules for ABO Blood Type • A and B are codominant • AA = Type A • BB = Type B • AB = Type AB • A and B are dominant over O • AO = type A • BO = type B • OO = type O

  7. Human A B O Blood Types: • TYPE _A_ • Allele = IA • Blood cells have small antigens on the surface.

  8. A B O Blood Types • TYPE _B_ • Allele = IB • Cells coated with type B antigens

  9. A B O Blood Types • TYPE _AB_ • genotype = IAIB • Blood cells contain both types of antigens • Known as universal recipient

  10. A B O Blood types • TYPE _O • Allele = i • No antigens on the surface of the blood cells • Known as universal donor

  11. Multiple alleles ABO blood groups Table 14.2 There are _3_ different alleles, IA, IB, and i Allele IA makes a cell surface antigen, symbolized with a triangle IB makes a different antigen, symbolized as a circle i makes no antigen

  12. 14. Use the results shown to determine the blood type for each sample. A To determine a person’s blood type, we add three different serums to blood samples and see if clumps form. Clumps = Positive (+)No Clumps = Negative (-)What would the blood type be for this sample? Rh + = Clump - = No Clumps B Blood Type: ___ #13 Blood Typing

  13. Multiple alleles ABO blood groups The Human ABO Blood Group System

  14. A A A A A Rh Rh Rh Rh Rh B B B B B Blood Type: ___ Blood Type: ___ Blood Type: ___ Blood Type: ___ Blood Type: ___ + = present - = absent Blood Typing Use the results shown to determine the blood type for each sample.

  15. How common are the different blood types? 45 % 40 % 4 % 11 %

  16. AO AO BO BO Problem: Multiple Alleles • Show the cross between a mother who has type O blood and a father who has type AB blood. O O GENOTYPES: - AO (2) BO (2) - ratio 1:1 A B PHENOTYPES: - type A (2); type B (2) - ratio 1:1

  17. BO AB AO OO Problem: Multiple Alleles • Show the cross between a mother who is heterozygous for type B blood and a father who is heterozygous for type A blood. GENOTYPES: A O • AB (1); BO (1); • AO (1); OO (1) • - ratio 1:1:1:1 B O PHENOTYPES: • type AB (1); type B (1) • type A (1); type O (1) • - ratio 1:1:1:1

  18. Polygenic traits • Traits controlled by two or more _genes_. • Examples: • Human height, eye and skin color

  19. SEX DETERMINATION & SEX-LINKED INHERITANCE

  20. SEX DETERMINATION • The greatest difference between individual members of the same species is their sex.

  21. IDENTIFY THIS KARYOTYPE

  22. SEX DETERMINATION • In humans, females have two “X” chromosomes in the 23rd pair.

  23. SEX DETERMINATION • In humans, males have an “X” and a “Y” chromosome on the 23rd pair.

  24. HOW IS SEX DETERMINED? • If females have the XX combination, then all eggs will contain an X chromosome. X XX X

  25. HOW IS SEX DETERMINED? • If males contain the XY combination then the sperm can contain either the X or the Y chromosome. X XY Y

  26. THEREFORE, • The male always determines the sex of the offspring--if he passes the X chromosome the result is a female offspring. • If he passes the Y chromosome the result is a male offspring.

  27. SEX-LINKED INHERITANCE

  28. THE DISCOVERY OF SEX LINKAGE • The study of the fruit fly by Thomas Hunt Morgan led to the discovery of sex determination and sex linkage.

  29. MORGAN’S EXPERIMENT • Most flies had red eyes. • Morgan noticed a male with white eyes. • He performed an experimental cross.

  30. WHITE EYED MALE RED EYED FEMALE P1 ?????????????????

  31. ALL OFFSPRING HAD RED EYES AND THE MALE TO FEMALE RATIO WAS 50:50

  32. WHAT WOULD YOU PREDICT IF TWO OF THE F1 FLIES WERE CROSSED? • A red eyed female crossed with a red eyed male?

  33. MORGAN FOUND: • 75% had red eyes, 25% had white eyes. • 50% were male, 50% were female • All of the white eyed flies were MALE.

  34. SEX-LINKED TRAIT • A trait that is carried on the X chromosome. • Almost always expressed in males.

  35. SEX-LINKED TRAITS IN HUMANS • Hemophilia • Duchenne Muscular Dystrophy • Red/Green Color Blindness

  36. ARE YOU COLOR BLIND?

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