1 23 Notes 23 01 2014 09 49 00 Watson and Crick nobel prize discovered structure of DNA Rosalind Franklin drafted the information and worked with the men but died dead ppl cant get nobel prize do x ray structure analysis to see the helix 4 discoveries needed to solve DNA structure 1 Phosphate backbone is on outside 2 Bases on inside 3 Molecule double helix 4 Strand antiparallel with specific base pairing wilkins head of the group so he got nobel prize too 3 ppl max Smoking molecules change when you smoke Cytidine deamination cytosine changes to uracil end result DNA is changed permanently from ACG ATG diff proteins coded for AMES test for mutagens take bacteria see if chemical causes mutations in bacteria developed by professor AMES expose bacteria to a test compound cigarette smoke tar and hair dye mutagenic compounds digestion can mutate chemicals fail ames test Cause mutation and is dangerous Human Genetics 35 million differences b w humans and chimps 98 similar although only 2 is different that is a HUGE AMOUNT small dna difference accounts for how we speak and our ability to speak everyone is always mutating and genetically different 1 mistake for 1 million replicated base pairs dna in each new cell should have 3000 mutations BUT all cells have mutation recognition and repair systems BUT not all are noticed so they aren t all fixed SNP snip single nucleotide polymorphism alternative to genome sequencing Usually differences correlate with some issue disease health BUT ARE NOT THE CAUSE FDA demands this info to be stopped because people don t understand it and seek unneeded medical care You can have a a mixture of snps because of dna from both mom and dad Isolate DNA look for a difference based on dye and the colors what do you do if you are positive for copies of early onset breast cancer mutations you carry gene tied to cancer what do you do Do you tell your kids Angelina jolie did that got boobs removed because she had a high risk PREVIVORS Somatic Cells skin all but reproductive mutations do happen but genetic info found in cells build repares replaces cells mutation during development or repair but AFTER fertilization mutations in skin cells gives people different colored skin OR if your pre iris cells are damaged you will have different colors in your eyes CELLS CAN RESULT IN CANCERS cells grow contact each other stop growing contact inhibition genes make proteins that stop more cell division but if you need cell division get cut and need skin to heal if you lose the ability for cells to stop growing lose repression then you get a tumor breast tissue very susceptible to this because its need to grow stop growing breast cancer easily inherited because receive those mutations and the lack of control to repress not Human hereditary diseases can t catch it its because of a genetic difference Chromosome translocations part of chromosomes move chromosome nondisjunctions during sperm egg development they should ve come apart and didn t can occur with any autosome or a sex chromosome non disj w xx pair Egg with two x chromosomes and egg without an x chromosome no sex chromosome trisomy x or x 0 turner syndrome or xxy klinefelter syndrome 1 30 Notes 23 01 2014 09 49 00 Jacob Syndrome two y chromsomes non disjunct Causes xyy so get tall guys with speech and learning issues tall thin acne immaturity etc Why are there more men in prison with XYY Ugly not a part of the group genetic predisposition to criminal behavior DNA Sequenced most people said yes Genomic DNA Mitochondrial DNA SNP on the test so know it Autosome Non disjunction trisomy 3 copies of one chromosome trisomy 13 patau syndrome small head eyes cleft lip trisomy 18 Edward syndrome heart and development issues trisomy 21 down syndrome older women have increased risk of having down syndrome children mental retardation heart defects occur see differences in the eyes hands and ears Single Gene Mutation Traits 2 copies of EVERY gene in every somatic cell one parent except for genes on x and y chromosomes in males if BOTH are identical Homozygous for that gene if genes are NOT same then heterozygous for that gene different versions of the same gene alleles ex gene is eye color allele is brown blue dominant allele trait in homozy heterozy individuals recessive allele expressed only in homozy Individual on the X or Y chromosome it s expressed in MALES because only have 1 copy of x and y Autosome all but x and y chromosomes single gene linked traits widows peak peak dominant earlobes unattached dominant others bent pinky dominant mid digit hair hair on middle finger dominant tongue rolling hitchhikers thumb dimples freckles etc Sex chromosome linked single gene traits ex red green color vision X chromosome gene responsible for color vision mutations that cause loss of color vision recessive Females have TWO x chromosomes so its really rare to be color blind but males only have ONE x chromosome so they have higher chances more frequent in males Human Genetic Traits Hereditary Diseases Tay Sachs Cystic Fibrosis chloride channels fail mucus in lungs autosom nervous system failure autosomal recessive recessive Sickle cell disease anemic disease autosomal incomplete dominant Achondroplasia dwarfism autosomal dominant Huntingtons mental deterioration autosomal dominant Human Pedigrees Genetic counseling graduate program osu first class next fall construct pedigrees to show if traits are dominant recessive and how likely it is in the family consanguineous relationship married cousins are more likely to have recessive trait more marry your own blood see arrow above disorders Queen Victoria ON TEST PAY ATTENTION Mutation in gene responsible for blood clotting hemophila on the x chromosome then can prevent clotting from those who have the gene on one or both chromosomes profuse bleeding on the x chromosome which gets passed on very rare lots of royalty marriage each other but all of her great grandkids died before they could even have kids again all of the were males with die very young almost ALL died because of hemophilia blood clotting shows recessive gene x chrom only when two x chrom That re both NOT present in current british royal family hemophila defect in blood clotting recessive trait carried on x chromosome so when present males are ALWAYS affected ABO Blood System hemophilia recessive a blood type a only b type b only ab type both on surface present co dominant a and b because neither is dominant and both can be Paternity