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Biology 101 A

Biology 101 A. Genetics Unit. Today’s Agenda. Topic: Multiple Alleles Due Today: Pedigree assignment from yesterday Blue People Case Study Dihybrid crosses if you haven’t already turned it in. Getting Started, 10-25. The disorder on the pedigree is recessive.

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Biology 101 A

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  1. Biology 101 A Genetics Unit

  2. Today’s Agenda • Topic: Multiple Alleles • Due Today: • Pedigree assignment from yesterday • Blue People Case Study • Dihybrid crosses if you haven’t already turned it in

  3. Getting Started, 10-25 • The disorder on the pedigree is recessive. • Which individuals should be ½ shaded indicating they are a carrier?

  4. After your quiz- • STAY AT YOUR SEAT… • We’re going to grade them all together

  5. Weird Punnett Notes • Why are they referred to as “weird”? • What are some examples?

  6. What is meant by “multiple alleles”? • Multiple alleles: more than two alleles control a trait • Can also be called polygenic • Ex: height, hair color, eye color and blood type • How can you tell? Lots of variation in traits • .

  7. How is blood type inheritance an example of multiple alleles? • Blood type is determined by the presence or absence of proteins on surface of red blood cells • Blood types: A, B, AB and O

  8. Practice • Cross 2 parents with O blood. Can they have a child with B blood? • Can 2 parents with B blood have a child with O blood? • If you were asked to cross 2 people with A blood, how many punnetts would that require?

  9. Multiple Allele Assignments • Everyone is doing same assignment today regardless of group number- Multifactorial LAB • ½ class starts with Eye analysis at TABLE ONE • ½ class starts with Height analysis at TABLE THREE • Homework: Blood crosses- front table

  10. Before class starts… • Put up your electronic devices, food and drinks • Get out your notebook and open it to your unit assignment sheet

  11. You should have back: #9 and #10- stapled together: Monohybrid crosses and Dihybridcrosses #11- Solaron Quiz #13- Kentucky Blues case study (stamped) #14- Pedigree Assignment #15- Pedigree Quiz

  12. This week’s schedule • Monday- Sex-Linked Traits • Tuesday- Co/Incomplete Dominance Traits • Wednesday- Evolution Pretest and Genetics Station Review • Thursday- Unit test and Project due • Friday- Start Evolution unit

  13. Getting Started, 10-28 • A wealthy elderly couple die together in an accident. Soon a man shows up to claim their fortune, saying that he is their only son who ran away from home as a boy. • Other relatives dispute his claim. Hospital records show that the deceased couple were type AB and O respectively. The claimant to the fortune was type O. Could he be their son? Explain.

  14. Get out your notes we started last class • Today- Sex-linked traits

  15. What are sex-linked alleles? • What? Sex-linked alleles: controlled by genes located on sex chromosomes • Where? Usually carried (found) on X chromosome • How do you know? Last pair of chromosomes are sex chromosomes • Why? Since females are XX, they are usually carriers of the trait • Why? Since males are XY, they have a higher tendency for inheritance of trait

  16. Sex-linked cont. • Examples: colorblindness, hemophilia • How different? • Have to show sex chromosomes on punnett

  17. Steps to work: • Draw your punnett- with 4 boxes • Put male chromosomes at top (XY) • Put female chromosomes on side (XX) • Write in sex chromosomes for offspring • Assign letters for parents • Then do letters for children

  18. Fill in chart

  19. DUE TODAY Assignment #18- Multiple Allele Lab (eye/height) Assignment #17- Blood Cross Problems

  20. Today’s assignments EVERYONE HAS 2 ASSIGNMENTS: Sex-linked problems AND Multiple crosses Problems are in BLUbasket at my desk

  21. Quick Quiz 10-22 • Sex-linked traits are typically found on the ___ chromosome. a. X b. Y c. X and Y equally 2. If someone has B blood type, how many genotypes can they have? a. BB only b. BO only c. BB and BO 3. What is the chance that two parents with O blood can have a child with A blood? a. zero b. 50% c. 75% d. 100% 4. Why do males have a higher chance of showing a sex-linked trait than females?

  22. Before class starts… • Get your notebook out, be ready for class to start • Due Today: Assignment #18: Sex-linked crosses Assignment #19: Multiple & Sex-linked problems

  23. You should have back today: #16- Multiple allele assignment Blood Crosses- we’re going to check these togehter

  24. Quick review • A man has type A blood and his wife has type B. A physician types the blood of their four children and is amazed to find one of each of the blood types among them. How could this happen? • A woman sues a man for the support of her child. She has type A blood, her child has type O, and the man has type B. Could the man be the father? Explain.

  25. Today’s topic: • Incomplete and Codominant Traits

  26. Describe traits that are neither dominant or recessive • Incompletely dominant: • Genotype is heterozygous (hybrid) • Phenotype is between two parents • Dominant gene cannot fully inhibit the recessive • Ex: white flower x red flower = pink flowers

  27. Incomplete Practice problems • If black and white fur colors are incompletely dominant in cats, what would be the result of crossing a black cat and a white cat? • What would be the result if you crossed two of the offspring above?

  28. Neither dominant or recessive • Codominant: • Offspring shows phenotype of neither parent • Both alleles are dominant • Ex: black chicken x white chicken = checkered chicken

  29. Practice problems What would the results be in a cross between a black chicken and a checkered chicken? • What would the results be between two checkered chickens?

  30. Today’s assignments Expect Quiz at end of class on “weird punnetts”

  31. Binder Cleanout

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