Will I need therapy after this class?

Will I need therapy after this class? Lecture 14 - Genetics

Mendel Founder of modern genetics called classical genetics or Mendelian genetics http://images.google.com/imgres?imgurl=eesc.orst.edu/agcomwebfile/magazine/99Spring/Images/mendel!.gif.gif&imgrefurl=http://eesc.orst.edu/agcomwebfile/magazine/99Spring/OAPSpring99text/OAPSPRG9906.html&h=172&w=198&prev=/images%3Fq%3DMendel%26start%3D40%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN

Mendel’s garden in Austria http://images.google.com/imgres?imgurl=nitro.biosci.arizona.edu/courses/EEB320/Lecture03/pics/medgard.jpeg&imgrefurl=http://nitro.biosci.arizona.edu/courses/EEB320/Lecture03/Lecture03.html&h=284&w=384&prev=/images%3Fq%3DMendel%2527%2Bgarden%26start%3D20%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN

Mendel (Genetics) vs (?) Darwin (Evolution) Worked in mid 1800s Saw work of the other as contradictory to their own work Mendel’s work now explains Darwin’s work

Mendel studied inheritance of garden pea anatomy and described meiosis without knowing anything about meiosis

........such as shape, color and texture of pea seeds.

Morgan advanced Mendel’s ideas using fruit flies. http://images.google.com/imgres?imgurl=www.amphilsoc.org/library/images/genetics/morgan2.jpg&imgrefurl=http://www.amphilsoc.org/library/guides/genetics.htm&h=329&w=300&prev=/images%3Fq%3Dmorgan%2Bgenetics%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8

Next……………………………… Some genetics terms and concepts

Gene = that section of DNA responsible for trait (seed color, eye color, skin color, etc.) Chromatin Gene

Genes Genes make protein products Alleles are alternate forms of gene for same trait Hemoglobin normal gene = H Hemoglobin sickle cell gene = h(allele)

Genotype Genotype is combination of genes responsible for traits or products. Three possibilities for genes H and h: HH and hh and Hh HH and hh = Homozygous Genotypes Homo = same zygous = union; Hh = Heterozygous Genotype Hetero = other zygous = union

Egg sperm H H h h HH Homozygous genotypes hh Normal zygote h H zygote with sickel cell Heterozygous genotype Hh Normal zygote

Phenotype Physical, chemical, physiological, behavioral appearance of organism

Review - Gene, Genotype & Phenotype Phenotype = normal red blood cell PHENOTYPE = normal hemoglobin GENOTYPES = HH or Hh H = normal hemoglobin GENE h = abnormal hemoglobin GENE PHENOTYPE = abnormal hemoglobin Phenotype = sickled red blood cell GENEOTYPE = hh

Types of genetic interactions following amphimixis: Dominance / recessiveness Incomplete Dominance Codominance Pleiotropy Atavism Multiple Alleles at the same loci

Dominant / Recessive Alleles Dominant allele - homozygous or heterozygous genotype = same phenotype Recessive allele – phenotype only shows up in homozygous genotype Alleles Genotypes Phenotypes T (tall plant) TT Tall Plant t (short plant) Tt Tall Plant tt Short Plant

G = allele for green seed pods is dominant g = allele for yellow pods is recessive gg GG or Gg

Polydactyly due to dominant gene (P); normal is due to recessive allele (p) PP or Pp genotype syndactyly pp is normal PP or Pp

Attached and Free earlobes Genotypes ff FF or Ff Phenotypes attached Free

Several types of interactions: Dominance / recessiveness Incomplete Dominance Codominance Pleiotropy Atavism Multiple Alleles at the same loci

Incomplete Dominance neither allele is completely expressed when the other allele is present. Genes Genotypes Phenotypes R (red flower) RR Red W (white flower) WW White RW Pink WW RW RR

Codominance equal expression of two alleles that occur at the same loci on homologous chromosomes Genes Genotypes Phenotypes IA IAIA Blood type A IB IBIB Blood type B i ii Blood type O IAIB Blood type AB IAi Blood type A IBi Blood type B IA and IB are codominant to each other, but dominant to i

Type “A” protein in membrane Type A blood is IAIA or IAi Type “B” protein in membrane Type B blood is IBIB or IBi Type “A” and type “B” proteins in membrane Type AB blood is IAIB Neiter Type “A” or type “B” proteins in membrane Type O blood is ii

Pleiotropy = single gene has have multiple effects

Bad hemoglobin protein = bad cells

Bad cells = bad physiology

Bad physiology = organ failures and “bad” life Key word is ……BAD

Atavism Traits similar to ancestral evolutionary traits. Examples include: human tail, mammary line, human gill slits May be due to: ancient genes mutations resulting in traits that resemble ancient traits

Human gene pool Normal allele is N atavistic allele is W and rare NN = normal NW = normal WW = atavism N N N W W N N N N N W N N N N

Human Tail is an example of Atavism or a form similar to an ancestral form

Mammary line - atavistic trait resulting in multiple mammary glands in humans; as is found in other more primitive mammals

There have been some documented cases of humans born with gill slits in neck without gills – very controversial little agreement on origin.

Several types of interactions: Dominance / recessiveness Incomplete Dominance Codominance Lethal Alleles Pleiotropy Multiple Alleles at the same loci

Si S Sp Sw least Order of dominance S – solid black Si – Black with some white Sp – white with some black Sw = all white Alleles Black and white coat color in dogs. Multiple Alleles at the same loci. 3 or more alleles at same loci within a population. Genotypes and Phenotype

genotypes S S or S Si or S Sp or S Sw phenotype S – solid black Si – Black with some white Sp – white with some black Sw = all white

Phenotype = Black with some white genotypes Si Si or Si Sp or Si Sw S – solid black Si – Black with some white Sp – white with some black Sw = all white

genotypes Sp Sp or Sp Sw S – solid black Si – Black with some white Sp – white with some black Sw = all white Phenotype = White with some black

S – solid black Si – Black with some white Sp – white with some black Sw = all white Sw Sw

Will I need therapy after this class?