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Di hybrid Crosses

Di hybrid Crosses. 1. Di-hybrid Crosses. Dihybrid crosses predict the probabilities of the combinations of two factors. Example: An individual who is heterozygous for both brown eyes and brown hair has offspring with another individual who is heterozygous for both traits.

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Di hybrid Crosses

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  1. Di hybrid Crosses

  2. 1. Di-hybrid Crosses • Dihybrid crosses predict the probabilities of the combinations of two factors. • Example: An individual who is heterozygous for both brown eyes and brown hair has offspring with another individual who is heterozygous for both traits. • Brown hair (H) is dominant to red (h) • Brown eyes (E) are dominant to blue (e)

  3. g. Dihybrid Crosses

  4. g. Dihybrid Crosses

  5. g. Dihybrid Crosses

  6. g. Dihybrid Crosses

  7. g. Dihybrid Crosses

  8. g. Dihybrid Crosses

  9. g. Dihybrid Crosses

  10. g. Dihybrid Crosses

  11. g. Dihybrid Crosses

  12. g. Dihybrid Crosses

  13. g. Dihybrid Crosses

  14. g. Dihybrid Crosses

  15. g. Dihybrid Crosses

  16. g. Dihybrid Crosses

  17. g. Dihybrid Crosses

  18. g. Dihybrid Crosses

  19. g. Dihybrid Crosses

  20. c. How many offspring have….. • Dark hair and brown eyes? HxEx? • Dark hair and blue eyes? Hxee? • Red hair and brown eyes? hhEx? • Red hair and blue eyes? hhee?

  21. How many offspring have….. • Dark hair and brown eyes? HxEx? nine • Dark hair and blue eyes? Hxee? • Red hair and brown eyes? hhEx? • Red hair and blue eyes? Hxee?

  22. How many offspring have….. • Dark hair and brown eyes? HxEx? nine • Dark hair and blue eyes? Hxee? three • Red hair and brown eyes? hhEx? • Red hair and blue eyes? hhee?

  23. How many offspring have….. • Dark hair and brown eyes? HxEx? nine • Dark hair and blue eyes? Hxee? three • Red hair and brown eyes? hhEx? three • Red hair and blue eyes? Hxee?

  24. How many offspring have….. • Dark hair and brown eyes? HxEx? nine • Dark hair and blue eyes? Hxee? three • Red hair and brown eyes? hhEx? three • Red hair and blue eyes? Hxee? one

  25. 2. Polygenic Inheritance

  26. F. Polygenic Inheritance Traits in which the phenotypes are determined by many genes contributing to the overall phenotype. Each gene is on a different location on the chromosome and may not even be on thesamechromosome. The best way to recognize polygenic inheritance is when the phenotypes exhibit a wide range of expression or variation. Examples:

  27. skin color

  28. Eye Color & Hair Color

  29. i. The best example for humans is blood. There 3 alleles for blood types in humans: A, B and O. A and B are co dominant while O is recessive. d. Multiple Alleles – Instead of having two forms of an allele, there are more than two for one gene.

  30. Type A genotypes could be: IAIA orIAi. Type B genotypes could be: IBIB or IBi. Type AB genotype is: IAIB Type O genotype is: ii b. Multiple Alleles – Blood Type

  31. Practice A man who is heterozygous for type A blood marries a woman who is heterozygous for type B blood. Find the possible outcomes

  32. Sex linked traits – Are genes located on the X chromosome. There is almost no information located on the Y chromosome. Since males have only one X chromosome they show whatever allele is on the X chromosome, regardless of whether it is dominant or recessive. e. Sex linked traits

  33. iii. This is the only time that a single recessive allele is expressed. Two examples of sex-linked traits in humans are red/green colorblindness and hemophillia. (A recessive sex linked trait that keeps your blood from clotting.) e. Sex linked traits

  34. Color Test

  35. Color Test

  36. Color Test

  37. Color Test

  38. If normal vision (N) is dominant to colorblindness (n) give the genotypes for each of the following: A female carrier: XNXn A homozygous dominant female: XNXN Colorblind male: XnY Colorblind female: XnXn A male with normal vision: XNY Sex linked traits - Colorblindness

  39. Who does the male get the X chromosome from? Mother Who does a male inherit recessive sex linked traits from? Mother Who are colorblind more often, men or women? Men; no information on Y to mask the recessive trait on X. Sex linked traits

  40. Practice A female carrier has a child with a male with normal vision. What are the chances of colorblindness occuring in: Son? Daughter?

  41. Practice A colorblind male has a child with a normal female. Fill out the cross.

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