Gene$cs: Part V. Extending Mendel APGRU5L5

Transcription

1 Gene$cs: Part V Extending Mendel APGRU5L5

2 Do Now: 1. The Mother is blue, father is white. The offspring is checkered blue and white. Is this co-dominance or incomplete dominance? 2. A black cat and a white cat have a litter of offspring. Name two potential phenotypes: 1) if coat color is incompletely dominant 2) if coat color is co-dominant.

3 Objective SWBAT understand Blood type pedigrees

4 Extending Mendelian Genetics for a Single Gene Inheritance of characters by a single gene may deviate from simple Mendelian patterns in the following situations: When alleles are not completely dominant or recessive When a gene has more than two alleles When a gene produces multiple phenotypes

5 Degrees of Dominance Complete dominance occurs when phenotypes of the heterozygote and dominant homozygote are identical In incomplete dominance, the phenotype of F 1 hybrids is somewhere between the phenotypes of the two parental varieties In codominance, two dominant alleles affect the phenotype in separate, distinguishable ways

6 What is blood type? Although all blood is made of the same basic elements, not all blood is alike. Blood types are determined by the presence or absence of certain antigens substances that tell the immune system to attack! These antigens are called A, B, and Rh (+ if you have it, - if you don t)

7 7 Human blood types are example of a trait governed by multiple alleles that express codominance. The four different types ( A, B, AB, and O) are named based on the enzyme that attaches a specific type of carbohydrate to the blood cells. Multiple Alleles

8 Figure (a) The three alleles for the ABO blood groups and their carbohydrates Allele I B i Carbohydrate A B none (b) Blood group genotypes and phenotypes Genotype or i I B I B or I B i I B ii Red blood cell appearance Phenotype (blood group) A B AB O

9 9 To solve genetics problems involving blood types, you need to keep the key in mind. There are two genotypes for both type A and type B blood. There is only one genotype for AB (AB) and one genotype of type O (ii)ey to blood type genotypes

10 Solve It 10 Sara, who is type O, claims that Ira is the father of her baby. The baby has type O blood. Ira is blood type B. Is it possible that Ira is the father?

11 11 Solve It

12 Blood Typing Key Point #1: Blood type has three alleles:, I B, and i. & I B are dominant i is recessive Blood Type B

13 Different genes code for markers A = B = O = no marker Person with AB AB AA or AO BB or BO Blood Type: AB Blood Type: A Blood Type: B

14 Quick Draw! A = triangle B = Square O= no marker 1. Draw is surface molecules 2. Assign the blood type Ex: Ex: AO AB Blood Type: A Blood Type: AB

15 Quick Draw! A = triangle B = Square 1. Draw is surface molecules 2. Assign the blood type Ex: AB AO BB OO Blood Type: AB

16 Blood Types = Type A (homozygous) i = Type A (heterozygous) I B I B = Type B (homozygous) I B i = Type B (heterozygous) I B = Type AB i i = Type O

17 learn-about-blood/blood-types Group A has only the A antigen on red cells Group B has only the B antigen on red cells Group AB has both A and B antigens on red cells Group O has neither A nor B antigens on red cells

18 Blood Typing Show the potential offspring between a mother who is homozygous for Type A blood and a father who is homozygous for Type B blood. GENOTYPES: i: 0% I B i: 0% I B : 100% ii: 0% PHENOTYPES: Type A: 0% Type B: 0% I B I B Type AB: 100% Type O: 0% I B I B I B I B

19 WHO DAT BABY DADDY?

20 Maury Show! We will use what we learned to find out who the daddy is Correct answers will be given a ticket, if the board is up when I ask for it!

21 Scenario 1 Katie is heterozygous for Type A blood ( i). Her baby is type O (ii). She is not sure if Richard, her husband, or Adam, her husband s best friend, is the father Richard has type AB blood ( I B ) Adam has type B blood (I B O)

22 Katie s baby is type O (OO). Who is the father?!?!?! Adam Richard I B i I B I B i AB Katie i I B i ii i i BO

23 Scenario 2 Samantha has type AB blood and so does her baby. She is not sure whether Nick or Ron is the father of her baby. Nick has type O blood Ron has type B blood (homozygous) Which one is the father? Use Punnett Squares to prove it.

24 Samantha has type AB blood and so does her baby. Nick i i Nick could not have a child i i with Samantha Sam who has AB I B I B i I B i blood!!!!! So, Ron is the dad!

25 Scenario 3 Nesha is homozygous for Type B blood. Her baby is heterozygous for Type B blood. She is not sure if Thomas, her personal trainer, or Jonny, her brother-inlaw, is the father Thomas has Type I B blood Jonny is heterozygous for Type A blood

26 Nesha s baby is heterozygous for Type B blood. Who is the father?!?!?! Thomas Jonny I B i I B I B I B I B I B I B I B i Nesha I B I B I B I B I B I B I B i

27 Scenario 4 Jackson is heterozygous for Type B blood, and his mother has Type AB blood. His father has Type AB blood, also. What does this mean?! (Prove your answer with a Punnett Square!)

28 JACKSON IS ADOPTED (OH SNAP!!!) I B I B ackson is I B i I B I B I B I B

29 Scenario 5 Liz has Type O blood, and her mother is heterozygous for Type A blood. She isn t sure who her father is. Terrance, her mother s pool boy, is heterozygous for Type A blood. Simon, her grocery clerk at Rouse s, is heterozygous for Type B blood.

30 Lizzeh has Type O blood, and her MAURY CAN T FIGURE mother is heterozygous for Type A THIS ONE OUT!!!! Terrance Simon i I B i i I B i Mother i i ii i I B i ii

31 Influence of Environment Another departure from Mendelian genetics arises when the phenotype for a character depends on environment as well as genotype The norm of reaction is the phenotypic range of a genotype influenced by the environment For example, hydrangea flowers of the same genotype range from blue-violet to pink, depending on soil acidity