This study source was downloaded by 100000842981794 from CourseHero com on 03 15 2022 01 10 31 GMT 05 00 https www coursehero com file 14621959 BloodTypeGeneticsProtocol Using Blood Tests to Identify Babies and CriminalsCopyright 2012 by Drs Jennifer Doherty and Ingrid Waldron Department of Biology University of Pennsylvania1I Were the babies switched Two couples had babies in the same hospital at the same time Michael and Danielle had twins a boy Michael Jr and a girl Michelle Denise and Earnest had a girl Tonja Danielle was convinced that there had been a mix up and she had the wrong girl since Michael Jr and Tonja were both light skinned while Michelle had darker skin Danielle insisted on blood type tests for both families to check whether there had been a mix up In order to interpret the results of the blood type tests you will need to understand the basic biology of blood types Blood TypesThere are many different ways to classify blood types but the most common blood type classification system is the ABO said A B O system There are four blood types in the ABO system Type A Type B Type AB and Type O These blood types refer to different versions of carbohydrate molecules complex sugars which are present on thesurface of red blood cells People with Have Type A bloodType A carbohydratemoleculeson their red blood cellsType B bloodType B carbohydratemoleculeson their red blood cellsType AB bloodType A and B carbohydratemoleculeson their red blood cellsType O bloodNeither A nor B carbohydratemoleculeson their red blood cellsThe Type A and Type B carbohydrate molecules are called antigens because they can stimulate the body to produce an immune response including antibodies Antibodies are special proteins that travel in the blood and help our bodies to destroy viruses or bacteria that may have infected our bodies see figure on next page 1 Teachers are encouraged to copy this Student Handout for classroom use A Word file which can be used to prepare a modified version if desired Teacher Preparation Notes comments and the complete list of our hands on activities are available at http serendip brynmawr edu sci edu waldron 1 This study source was downloaded by 100000842981794 from CourseHero com on 03 15 2022 01 10 31 GMT 05 00 https www coursehero com file 14621959 BloodTypeGeneticsProtocol Adapted from Figure 40 5 in Holt Biology by Johnson and RavenNormally our bodies do not make antibodies against any molecules that are part of our own bodies Thus antibodies help to defend against invading viruses and bacteria but normally antibodies do not attack our own body cells For example people with Type A blood do not make antibodies against the Type A antigen which is present on their red blood cells However they do make antibodies against the Type B antigen called anti B antibodies Test your understanding of blood groups by filling in the blanks in the chart below Blood group AIf you belong to the blood group A you have A antigens on the surface of your red blood cells and antibodies in your blood Blood group BIf you belong to the blood group B you have B antigens on the surface of your red blood cells and antibodies in your blood Blood group ABIf you belong to the blood group AB you have both A and B antigens on the surface ofyour red blood cells and no anti A or anti B antibodies in your blood Blood group OIf you belong to the blood group O you have neither A nor B antigens on the surface of your red blood cells but you have both and antibodies in your blood 2 This study source was downloaded by 100000842981794 from CourseHero com on 03 15 2022 01 10 31 GMT 05 00 https www coursehero com file 14621959 BloodTypeGeneticsProtocol Blood transfusions who can receive blood from whom If you are given a blood transfusion that does not match your blood type antibodies present in your blood can react with the antigens present on the donated red blood cells For example if a person who has Type A blood is given a Type B blood transfusion then this person s anti B antibodies will react with the Type B antigens on the donated red blood cells and cause a harmful reaction This reaction can cause the donated red blood cells to burst and or clump together and block blood vessels This type of transfusion reaction is illustrated in the following drawing Transfusion reactions can be fatal To prevent this from happening doctors test whether a person s blood is compatible with the donated blood before they give a transfusion A person can only be given donated blood with red blood cells that do not have any antigen that can react with the antibodies in the person s blood Test your understanding of blood groups by completing the table below Blood Group Antigens onred blood cells Antibodiesin plasmaCan receiveblood fromCan give blood toA AAnti B A and OA and AB B B AB A and B O None Which blood type would be considered a universal donor someone who can give blood to anyone Genetics of Blood Types Your blood type was established before you were born by genes inherited from your mother and father This blood type gene has three different versions or alleles that code for different versions of a protein enzyme as follows The IA allele codes for a version of the enzyme that puts Type A carbohydrate molecules on the red blood cells The IB allele codes for a version of the enzyme that puts Type B carbohydrate molecules on the red blood cells The i allele codes for an inactive version of the enzyme so red blood cells have neither type of carbohydrate molecule on their surface 3 This study source was downloaded by 100000842981794 from CourseHero com on 03 15 2022 01 10 31 GMT 05 00 https www coursehero com file 14621959 BloodTypeGeneticsProtocol Everyone has two copies of these genes so there are six possible combinations of alleles called genotypes which result in the four possible blood types phenotypes IA IA and IA i both resulting in Type A blood IB IB and IB i both resulting in Type B blood IA IB resulting in Type AB blood i i resulting in Type O blood In a heterozygous IA i person which allele is dominant IA or i Explain your reasoning Codominance refers to inheritance in which two alleles of a gene each have a different observable effect on the phenotype of a heterozygous individual Thus in codominance neither allele is recessive both alleles are dominant Which one of the genotypes shown above results in a phenotype that provides clear evidence of codominance Give the genotype and draw a picture of a red blood