Presentation on theme: "Different Patterns of Inheritance"— Presentation transcript:
1 Different Patterns of Inheritance Blood Types, Sex-Linked and PolygenicTraits
2 Blood Typing!PhenotypeGenotypeAAA or AOBBB or BOABOOO
3 AB-, AB+, A-, A+, B-, B+, O-, O+ blood Blood TypesType O-negative blood does not have any antigens.It is called the "universal donor" type because it is compatible with any blood type.Type AB-positive blood is called the "universal recipient" type because a person who has it can receive blood of any type.+ = have Rh protein- = no Rh proteinA person who has:Can receive:A- bloodA-, O- bloodA+ bloodA-, A+, O-, O+ bloodB- bloodB-, O- bloodB+ bloodB-, B+, O-, O+ bloodAB- bloodAB-, O- bloodAB+ bloodAB-, AB+, A-, A+, B-, B+, O-, O+ bloodO- bloodO+ bloodO-, O+ blood
4 Blood Type Crosses! Samara is type AB Naveen is type A his mother was A, Father OWhat are their genotypes?What are their possible offspring’s blood types?PhenotypeGenotypeAAA or AOBBB or BOABOOOS= AB N = AO50% A25% AB25% B
5 Blood Typing! Kristina is type B Kyle is type A Is is possible for their child to be type O?PhenotypeGenotypeAAA or AOBBB or BOABOOO
6 Polygenics Multiple GENES affect the traits being expressed Skin color Hair colorEye color
7 How it works… Eye Color = Hazel Eye Color = Brown Skin Color = Tan Skin Color = Light
14 A family history of a genetic condition PEDIGREE CHARTSA family history of a genetic condition
15 What is a pedigree chart? Pedigree charts show a record of the family of anindividualThey can be used to study the transmission of ahereditary conditionThey are particularly useful when there are largefamilies and a good family record over severalgenerations.
16 Studying Human Genetics Pedigree charts offer an ethical way of studying human geneticsToday genetic engineering has new tools to offer doctors studying genetic diseasesA genetic counsellor will still use pedigree charts to help determine the distribution of a disease in an affected family
17 Symbols used in pedigree charts A marriage with five children, two daughters and three sons. The second born son is affected by the condition.Eldest child Youngest childNormal maleAffected maleNormal femaleAffected femaleMarriage
18 Organising the pedigree chart A pedigree chart of a family showing 20 individuals
19 Organising the pedigree chart Generations are identified by Roman numeralsIIIIIIIV
20 Organising the pedigree chart Individuals in each generation are identified by Roman numerals numbered from the leftTherefore the affected individuals are II3, IV2 and IV3IIIIIIIV
21 Different Patterns of Inheritance Sex-Linked RecessivePassed on the X or Y chromosomeUsually XWhat this means…Girls can be carriers (XX)Males either have it or are normal (XY)Examples:Hemophilia, color-blindness, muscular dystrophy
22 Sex-Linked Recessive males get their X from their mother fathers pass their X to daughters onlyfemales express it only if they get a copy from both parents.expressed in males if presentPossible Carriers in femalesShown by half filled circlesUsually more males show this!!Cannot have sick male, normal mother
23 Autosomal DominantAll unaffected individuals are homozygous for the normal recessive allele.
24 Autosomal Recessive All affected are homozygous. Incest matings are often (but not always) involved.Heterozygous are “normal”
25 Dominant vs. Recessive Autosomal Is it a dominant pedigree or a recessive pedigree?1. If two affected people have an unaffected child, it must be a dominant pedigreeD is the dominant mutant allele and d is the recessive wild type allele. Both parents are Dd and the normal child is dd.2. If two unaffected people have an affected child, it is a recessive pedigree:R is the dominant wild type allele and r is the recessive mutant allele. Both parents are Rr and the affected child is rr.3. If every affected person has an affected parent it is a dominant pedigree.
26 Dominant Autosomal Pedigree 1. If two affected people have an unaffected child, it must be a dominant pedigree12345678910IIIIII
27 Recessive Autosomal Pedigree If two unaffected people have an affected child, it is a recessive pedigree
28 Recessive Sex Linked Pedigree If I don’t tell you.. Look for shadingIf I tell you, shade it