2. 1 Genetics Simple Inheritance

3. Learning Intentions Understand that there are three types of simple inheritance Understand that there are three types of simple inheritance Dominant/Recessive Dominant/Recessive Sex linked Sex linked Intermediate/Codominance Intermediate/Codominance 2

4. 3 I wonder how, I wonder why I’m 61% like a fly? Now here’s a shock that’s sort of grouse We’re 99% like a mouse! It makes you stop, it makes you think How similar are we to a chimp? Source: Mouse http://animals.timduru.org/dirlist/mouse/mouse.jpg Drosophila: http://www.innate.se/drosophila.jpghttp://www.innate.se/drosophila.jpg Chimpanzee: http://www.utalii.com/Hotels/images/Chimpanzee.jpg WE ARE DIFFERENT IN MANY WAYS, BUT IN MANY WAYS WE ARE THE SAME!

5. We are 35% like a daffodil!!! We are 35% like a daffodil!!! 4

6. Simple Inheritance

7. 6 Discovering Small Differences Second toe longer or shorter than your big toe? Earlobes Attached or unattached? Cross your arms….are you left over right or right over left? Pull your hair back. Widows peak or none? Mid-digit hair on fingers?

8. Glossary Phenotype - The observable traits or characteristics of an organism, for example hair color, weight, or the presence or absence of a disease. Phenotypic traits are not necessarily genetic. Phenotype - The observable traits or characteristics of an organism, for example hair color, weight, or the presence or absence of a disease. Phenotypic traits are not necessarily genetic. Genotype- The genetic identity of an individual that does not show as outward characteristics. Genotype- The genetic identity of an individual that does not show as outward characteristics. Alleles – the forms of the gene e.g. tongue roller or not tongue roller Alleles – the forms of the gene e.g. tongue roller or not tongue roller Homozygous - Possessing the same form of a particular gene. E.g. TT or tt Homozygous - Possessing the same form of a particular gene. E.g. TT or tt Heterozygous - Possessing two different forms of a particular gene, one inherited from each parent. Eg. Tt Heterozygous - Possessing two different forms of a particular gene, one inherited from each parent. Eg. Tt

9. Dominant/Recessive Inheritance Dominant - A gene that almost always results in a specific physical characteristic, for example, a disease, even though the patient's genome possesses only one copy. With a dominant gene, the chance of passing on the gene (and therefore the disease) to children is 50-50 in each pregnancy. Dominant - A gene that almost always results in a specific physical characteristic, for example, a disease, even though the patient's genome possesses only one copy. With a dominant gene, the chance of passing on the gene (and therefore the disease) to children is 50-50 in each pregnancy. Recessive – used to refer to a gene whose parent phenotype is expressed only if present in a double “dose”. Recessive – used to refer to a gene whose parent phenotype is expressed only if present in a double “dose”.

10. How to write dominant – recessive genetic traits Widow’s Peak Widow’s Peak W widow’s peak present w straight hair line Ear Lobes Ear Lobes L free ear lobe l attached ear lobe Mid –digital hair Mid –digital hair H hair present h hair absent 9 Dwarfism Dwarfism D dwarf stature d normal stature Pigment Production Pigment Production A normal pigment produced a lack of pigment - albino Colour Blindness Colour Blindness X C Normal Colour Vision X c Red green colour blindness

11. My genetic recipe with these traits ww; ll; hh; dd; AA ; X C X C ww; ll; hh; dd; AA ; X C X Cor ww; ll; hh; dd; Aa ; X C X c ww; ll; hh; dd; Aa ; X C X c 10

12. AA means normal pigmentation AA means normal pigmentation Aa means normal pigmentation Aa means normal pigmentation Aa means you have albinism Aa means you have albinism X C X C means no colour blindness in girls X C X C means no colour blindness in girls X C X c means no colour blindness in girls X C X c means no colour blindness in girls X c X c means colour blindness in girls X c X c means colour blindness in girls 11

13. Genetic wheel Activity 12

14. Punnett Squares TT T T TT Genotype:TT Phenotype:all Tongue Roller

15. Punnett Squares tt t t tt Genotype:tt Phenotype:all Non Tongue Roller

16. Punnett Squares Tt T t TT Tt tt Genotype:1TT: 2Tt:1tt Phenotype:3/4 Tongue Roller:1/4 Non Tongue Roller

17. Punnett Squares Tt t t Tt tt Tt tt Genotype:Tt :tt Phenotype:1/2 Tongue Roller 1/2 Non Tongue Roller

18. 17 Is any other combination possible??

19. Sex – linked inheritance Review fertilization Review fertilization Sex organs – testes and ovaries Sex organs – testes and ovaries Gametes – sex cells Gametes – sex cells Ovum (ova) Ovum (ova) Sperm Sperm XX – female XX – female XY – male XY – male 18

20. Sex Linkage When characteristics are determined by genes on X chromosome. E.g. Haemophaelia When characteristics are determined by genes on X chromosome. E.g. Haemophaelia XhXh Y XX XX h XYXhYXhY Genotype: XX: X h X : XY: X h Y Phenotype:1 Normal Girl:1Carrier girl:I normal boy:I haem boy What genotype type would parents have to be to give birth to a girl with haemophilia? X h X (or X h X h) and X h Y X X In this case X is normal X h has the disease haemophilia

21. Pedigree-showing inheritance through generations A pedigree is used to show the pattern of inheritance of a particular characteristic or trait. These pedigrees Can then be used to work out if the trait is genetically inherited, and whether it is dominant or recessive. A pedigree is used to show the pattern of inheritance of a particular characteristic or trait. These pedigrees Can then be used to work out if the trait is genetically inherited, and whether it is dominant or recessive. In human pedigrees, a horizontal line joins two individuals who are married (or produce children together). A vertical line branching out from the marriage line shows their children. In human pedigrees, a horizontal line joins two individuals who are married (or produce children together). A vertical line branching out from the marriage line shows their children. Individuals that show a particular trait that is being followed are indicated by shading their symbol. Individuals that show a particular trait that is being followed are indicated by shading their symbol. Do handout Royal Family What type of inheritance is this? Do handout Royal Family What type of inheritance is this?

22. Haemophilia in Royal Family Pedigree P174 of text Questions 2 and 3 worksheet

23. Textbook Chapter 6.3 Handout Review question on simple imheritance P197 q 1-13 Pedigree Handout Review questions on pedigree P204 q 1-7

24. Intermediate Inheritance These are examples of partial dominance. There are two different types of intermediate inheritance These are examples of partial dominance. There are two different types of intermediate inheritance Incomplete dominance – when the heterozygous genotype is expressed as a a mixture of either homozygous genotypes. E.g. when a black mouse (BB) mates with a white mouse(WW) and all offspring are grey (BW). Incomplete dominance – when the heterozygous genotype is expressed as a a mixture of either homozygous genotypes. E.g. when a black mouse (BB) mates with a white mouse(WW) and all offspring are grey (BW). See Punnett Square activity on next slide See Punnett Square activity on next slide Co-dominance – where both alleles are present in a heterozygote are expressed Co-dominance – where both alleles are present in a heterozygote are expressed E.g. Human Blood Groups such as ABO blood group E.g. Human Blood Groups such as ABO blood group

25. Punnett Squares BB W W BW Genotype:BW Phenotype:All Grey

26. Intermediate/CoDominance WS

27. Blood Groups Example of Dominant/Recessive and Codominance A and B are codominant O is recessive to A and B Rhesus Factor i.e. whether you are positive or negative is dominant/recessive

28. Antibodies and Antigens Antibodies are Y-shaped proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses. Antibodies are Y-shaped proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses.proteins bloodbodily fluidsvertebratesimmune systembacteriavirusesproteins bloodbodily fluidsvertebratesimmune systembacteriaviruses An antigen or immunogen is a molecule that stimulates an immune response. An antigen or immunogen is a molecule that stimulates an immune response.immune

29. Rhesus factor You can also inherit Rh antigen; You can also inherit Rh antigen; If you are Rh+ you have the antigen If you are Rh+ you have the antigen If you are Rh- you do not If you are Rh- you do not What type of inheritance is this? What type of inheritance is this? W/S Baby may be AB W/S Baby may be AB