Introduction to Genetics

It all started here

The Beginnings of genetics Questions: Who is the father of genetics? What is genetics? Genetics - is the study of heredity or the study of passing of traits from parent to offspring * The father was Gregor Mendel HE.912.C.1.4 Analyze how heredity and family history impact health

What was known? Questions: Explain the types of chromosomes and their importance. What is the importance of meiosis? Why is fertilization important? Chromosomes determine everything about living things Come in pairs During meiosis they segregate to make a gamete (egg or sperm) Fertilization - pairs the chromosomes again The 2 types are autosomes and sex chromosomes SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. SC.912.L.16.17 Compare mitosis and meiosis and relate to the process of sexual and asexual reproduction and their consequences for genetic variations. HE.912.C.1.4 Analyze how heredity and family history impact health

When fertilization occurs … Each parent gives one of each pair of chromosomes

Importance of segregation Questions: What is segregation and why is it so important? Without segregation an offspring will not get the correct number of chromosomes – resulting in mutations or death Too many is called polyploidy Example: Down syndrome - extra 21st chromosome SC.912.L.16.1 Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. HE.912.C.1.4 Analyze how heredity and family history impact health

Extra 21

Extra 13

Mendel’s Discoveries Questions: On chromosome are genes What is the difference between a gene and allele? What 2 forms can alleles take? On chromosome are genes They determine a specific trait Gene have different forms called alleles Dominant alleles - strong (shown with a capital letter) Recessive alleles - weaker (shown with a lower case letter) SC.912.L.16.2 Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. HE.912.C.1.4 Analyze how heredity and family history impact health

Importance of alleles Questions: What is the difference between the genotype and phenotype? Typically there are 2 alleles that represent each trait This two letter combination is called the genotype TT or Tt or tt We use the genotype to determine what it looks like – called the phenotype SC.912.L.16.2 Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health.

Determining what the trait looks like Questions: What is the difference between a dominant and recessive trait? Dominant traits - are always seen RR and Rr both will show the dominant trait Recessive traits – only seen if there are no dominants present rr will show the recessive trait SC.912.L.16.2 Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. HE.912.C.1.4 Analyze how heredity and family history impact health

Determining what the trait looks like Codominance - both traits are seen Example: multicolored shells or cats SC.912.L.16.2 Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health.

Determining what the trait looks like Questions: What is the difference between codominance and incomplete dominance? Incomplete dominance – none are dominant so they mix Example: red flower plus white flower = pink flower SC.912.L.16.2 Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health.

Determining what the trait looks like Multiple alleles – when there are more than 2 alleles that control the trait But still only 2 letters in the genotype Blood type has A B and O A blood type: XAXA or XAXO B blood type: XBXB or XBXO AB blood type: XAXB O blood type: XOXO Questions: Explain what multiple alleles means and explain an example. SC.912.L.16.2 Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. HE.912.C.1.4 Analyze how heredity and family history impact health

Determining what the trait looks like Polygenic traits – have more than 2 genes for a trait that all effect the outcome The genotype has more than 2 letters (AAbbCc) Example - skin color, hair color, height Questions: What is a polygenic trait and why does it allow for so much diversity? SC.912.L.16.2 Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health.

Determining the possibilities Questions: What is probability and how is it used in determining the possible genetic outcomes? Probability – is the likelihood an event will occur In genetics the Punnett square is diagram used to determine the genetic probability of an offspring It tells you what the parents have, what the children could have, but it never tells you the actual outcome SC.912.L.15.15 Describe how mutations and genetic recombination increase genetic variation.

Using the Punnett Square Questions: What is the difference between homozygous and heterozygous? Why do you need to know the parent genotypes first? First - determine the genotypes both parents Homozygous dominant - both letters are capital Homozygous recessive - both letters are lower case Heterozygous - one letter is capital and the other is lower case SC.912.L.16.1 Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance.

Step 2: Fill in the square If B=brown eyes and b=blue eyes Cross a homozygous dominant and a homozygous recessive individual   B B Bb Bb b Bb Bb SC.912.L.16.1 Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance.

Interpreting the Punnett Square Questions: How do you find ratios and percentages for the Punnett square? Ratios Go from most dominant to most recessive Include genotypic ratios Include phenotypic ratios SC.912.L.16.1 Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance.

What if we look at more than one trait? Follow the Principle of independent assortment – says that genes for different traits segregate independently In other words – each parent will give one of each letter to the offspring Example: RrYy Possibilities alleles passed are RY Ry rY ry Questions: What does the principle of independent assortment state? Why is this idea important? SC.912.L.16.1 Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance. SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations.

Genetic disorders Dominant disorders – on the dominant genes All it takes is one bad gene and you have it Example: Achondroplasion - dwarfism Questions: What is a dominant disorder and why is it so dangerous? SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. HE.912.C.1.4 Analyze how heredity and family history impact health

Dwarfism

Primordial Dwarfism

Genetic disorders Recessive disorders – are on the recessive alleles If you have 2 recessive you have it If you have 1 you are a carrier Example: Cystic Fibrosis – mucus in lungs Albinism – no melanin Questions: What are recessive disorders? Why is being a carrier still dangerous? SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. HE.912.C.1.4 Analyze how heredity and family history impact health

Albinism

Genetic disorders Sex linked disorders – on the X and Y chromosomes If it is on the X Females – both parent must give it Males – only mom gives it If it is on the y Females – don’t get because no y Males – if dad has it all sons have it Examples on X: Baldness – loosing hair Hemophilia – blood can’t clot properly Questions: Why is it more dangerous for boys than girls when it comes to sex linked disorders? SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. HE.912.C.1.4 Analyze how heredity and family history impact health

Baldness

Color Blindness http://www.kcl.ac.uk/teares/gktvc/vc/lt/colourblindness/cblind.htm http://webexhibits.org/causesofcolor/2.html#vissamp

Genes affected by the environment Questions: How can environmental factors affect characteristics? Characteristics can be affected by the environment Examples: Nutrition affects height Scholastic verses non-scholastic home affect intelligence SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health.

Why organisms naturally different Questions: Explain organisms naturally differ? Crossing over Independendant assortment Mutations SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. HE.912.C.1.4 Analyze how heredity and family history impact health

How humans cause variations? Mutations – environmental or chemical Hybridization – crossing 2 dissimilar organisms Selective breeding – crossing 2 of same species Inbreeding – crossing organisms in the same family tree Genetic engineering - the process of man reading, editing, and reinserting pieces of DNA Questions: Explain how man has caused genetic difference in organisms. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both the individual and public health. SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. SC.912.L.16.10 Evaluate the impact of biotechnology on the individual, society, and the environment, including medical and ethical issues.

1. Extract DNA 2. Read the Sequence 3. Cutting the DNA 4. Separating DNA – using electrophoresis 5. Pasting – using enzymes 6. Making Copies

Cell Transformation in Bacteria Cell transformation - process of taking DNA from one cell into another cell They use bacteria Foreign DNA is joined to a circular DNA called a plasmid Plasmid is mixed with bacteria Treated with anti-bacteria to kill all cell except those with the new gene Questions: Explain how man has caused genetic difference in organisms. SC.912.L.15.15 Describe how mutations and genetic recombination increases genetic variations. SC.912.L.16.10 Evaluate the impact of biotechnology on the individual, society, and the environment, including medical and ethical issues.

Using Bacteria For Genetic Engineering