Honors Biology Ch. 11 Complex Inheritance and Human Heredity Complex Inheritance and Human Heredity

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  • Honors BiologyCh. 11Complex Inheritanceand Human Heredity

  • I.Human Inheritance- heredity in humans is the same as in other organisms- most genetic diseases are recessive and rare

  • A.Recessive Traits-diseases caused by a single defective gene/protein1.Cystic Fibrosis (CF)2.Tay-Sachs Disease3.Albinism4.Phenylketonuria (PKU)5.Sickle-Cell Anemia

  • DISORDEROCCURRENCE IN THE U.S.CAUSEEFFECTCURE-TREATMENTCystic Fibrosis1 : 3500(Mainly people of northern European descent)The gene that codes for a membrane protein is defective.*Excessive Mucus Production*Digestive and Respiratory Failure*No Cure*Daily Cleaning of Mucus from Lungs*Mucus-thinning DrugsAlbinism1 : 17,000Genes do not produce melanin.*No Color in Skin, Eyes & Hair*Prone to Skin Cancer and Cataracts*No Cure*Protect Skin from the SunTay-Sachs Disease1 : 2500 (Affects People of Jewish descent)Absence of a necessary enzyme that breaks down fatty substances*Buildup of Fatty Deposits in The Brain*Mental Disabilities*No Cure or Treatment*Death Occurs by Age 5

  • B.Dominant Traits 1.Huntingtons Disease-rare, degenerative nervous system disorder

  • 2.Achondroplasia-a disorder of bone growth-homozygous dominant condition is fatal

  • 3.Polydactyly

  • II.Other Inheritance PatternsA.Sex Chromosomes:- pair of chromosomes that determine an individuals sex XX - female XY - male

    Autosomes: the other chromosome pairs except the sex chromosomes

  • Human Chromosomes:44 Autosomes

  • Human Chromosomes:2 Sex Chromosomes

  • B.Sex-Linked Traits: -trait controlled by a recessive allele on the "X" sex chromosome-more common in males-Ex. Red-green color-blindness,hemophilia

  • Can you see a number?

  • Queen Victorias Family

  • Pedigree of Europes Royal Families

  • C.Sex-Influenced Traits: -trait controlled by an allele that is recessive in females and dominant in males-Ex. Male-pattern Baldness

  • D.Incomplete Dominance:-a trait in which the heterozygote shows a blending of traits-Ex. Carnations and Snap dragons: R - red, W - white, RW - pink

  • RRIncomplete Dominance: PHomozygous Red ParentHomozygous White ParentRWRWRWRWPinkPinkPinkPinkWW

  • RWIncomplete Dominance: F1Heterozygous Pink ParentHeterozygous Pink ParentRWRWRRWWRedPinkPinkWhiteWR

  • E.Codominance:-a trait in which the heterozygote shows both alleles equally-Ex. Horses: R - red, W - white, RW - roan-Ex. ABO Blood GroupsA B AB

  • E.Codominance:Roan Horses

  • E.Codominance:ABO Blood Groups

  • F.Polygenic Inheritance:-traits controlled by more than one pair of genes-Ex. hair, skin, and eye color

  • ABAbaBabABAbaBabHuman Eye ColorEGGSSPERMMotherAaBbFatherAaBbAABBAABbAaBBAaBbblackdark browndark brownlight brown

  • Human Skin Color

  • G.Epistasis -A gene at one locus alters the phenotypic expression of a gene at a second locus.- Example: black, brown, and white coat in mice

  • Epistasis: Black, Brown, and White Coat in Mice

  • H.Multiple Alleles:1.ABO Blood Groups: - 4 blood types: A, B, AB, O- caused by a protein in the membranes of red blood cells- 3 alleles for this protein: IA, IB, i

  • -Genotypes for the 4 blood types:Type A:IA IA, IAiType B:IB IB, IBiType AB:IA IBUniversal RecipientType O:iiUniversal Donor

  • 2.Rh Blood Groups:-an example of multiple alleles-there are about 8 dominant alleles (+)-one recessive allele (-)

  • III.Nondisjunction:-homologous chromosomes fail to separate during meiosis

  • III.Nondisjunction:-Down Syndrome (Trisomy 21)-Klinefelters Syndrome (XXY)- XYY Syndrome-Turners Syndrome (Monosomy X) (X)-Trisomy X (XXX)

  • Down syndrome(Trisomy 21)

  • Incidence of Down Syndrome

  • Turners Syndrome (Monosomy X)

  • XYY Syndrome

  • Trisomy X (XXX)

  • Klinefelters Syndrome (XXY)

  • Down Syndrome (Trisomy 21)

  • Normal Female

  • Edwards Syndrome (Trisomy 18)

  • IV. Fetal Testing:- Amniocentesis-Chorionic Villus Sampling- Ultrasound

  • Amniocentesis

  • Ultrasound image

  • Ultrasound Of Fetus

  • TheEnd

  • Human Chromosomes(23 homologous pairs)