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Jumpstart 12/3 A pea plant with the genotype TtWW is crossed with a pea plant with the genotype ttWw. How many different genotypes can be expressed in.

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Presentation on theme: "Jumpstart 12/3 A pea plant with the genotype TtWW is crossed with a pea plant with the genotype ttWw. How many different genotypes can be expressed in."— Presentation transcript:

1 Jumpstart 12/3 A pea plant with the genotype TtWW is crossed with a pea plant with the genotype ttWw. How many different genotypes can be expressed in the offspring? _____ (SHOW ALL WORK!) a. 1b. 2c. 3d. 4 How many different phenotypes? ______

2 Blood Types

3 Multiple Alleles More than two forms of a gene that code for a trait (more than 2 letters to represent the trait) Phenotype is still determined by a pair of alleles! The gene pool simply contains more than two. These alleles can be expressed in various ways:  Complete dominance  Co-dominance  Incomplete dominance

4 Multiple Alleles: Human Blood Type Blood Type is Coded by Multiple Alleles A, B, and O. *A and B are co-dominant. *A and B are completely dominant over O. Phenotypes Type A A B B AB Type O Genotypes AA AO BB BO AB OO *The genes cause the production of a cell surface protein A or B. Type O cells have neither protein, so Type O individuals are Universal DONORS. Which individuals are Universal RECEPIENTS (have both proteins)?

5 Blood Types… Blood from the donor to the recipient must be compatible. The problem occurs when the protein (antigen) outer layer of the RBC of a donor becomes coagulated (clumped) with the plasma proteins (antibodies) of the recipient.

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7 Blood Types… There are four different types of blood  A, B, AB, O They are determined by the protein (antigen) found on the RBC Type A, has protein (antigen) A on the RBC Type B, has protein (antigen) B on the RBC Type AB, has both protein (antigen) A and B on the RBC Type O, has neither protein (antigen) on the RBC

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9 Type A would have B agglutinins (antibody) in the plasma. Type B would have A agglutinins (antibody) in the plasma. Type AB would not have agglutinins (antibody) in the plasma. Type O would have A and B agglutinins (antibody) in the plasma.

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11 Type O is the universal donor, since it does not have antigens (proteins) on the surface of the RBC’s  It can be given to anyone and no clumping will occur! Type AB is the universal recipient, since it does not have agglutinins (antibody) in its plasma.  They can receive any blood since they have no antibodies!

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13 Multiple Alleles Many genes are present in 3 or more versions (alleles) – this is known as multiple alleles. The human ABO blood group is determined by three alleles (I A, I B, and i) of a single gene. The AB phenotype (genotype I A I B ) is an example of codominance!!

14 Codominance The human ABO blood group illustrates another genetic phenomenon – codominance. Codominance occurs when the phenotype associated with each allele is expressed in the heterozygote – both are expressed!

15 Problem 1 1. In humans, the blood types A, B, AB and O are determined by three alleles. A man who has AB blood marries a woman with O blood. What are the genotypes and phenotypes of the offspring?

16 Problem 2 2. A man who is heterozygous type A marries a woman who is heterozygous type B. What percentage of their offspring will be Type 0?

17 Problem 3 3. If a man with blood type B, one of whose parents had blood type O, marries a woman with blood type AB. What percentage of their children should have blood type B?

18 Problem 4 4. A man with type O blood and a woman with type AB blood get married. One of their children needs an operation. This child has type B blood. Can the child safely receive a blood transfusion from either parent? If not, why?

19 TOTD -Multiple Alleles:Who’s the baby daddy? You have been hired by Maury Povich to work for a show he is Having on Baby A - Type O Blood Baby B - Type B Blood Smiths - Types O and AB Jones - Types A and B 1 Baby C - Type AB Blood Baby D - Type A Blood 2 Squares -Types AB and AB Angles -Types AB and O


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