Chapters 11-12

*Genetics

*Vocabulary

*True-breeding

*Hybridization

*P generation

*F1 generation

*F2 generation

*Alleles

*Dominant

*Recessive

*Homozygous

*Heterozygous (hybrid)

*Laws

*Law of segregation

*Law of independent assortment

*Laws of probability

*http://www.bozemanscience.com/probability-in-genetics

*Degrees of dominance

*Complete dominance

*Incomplete dominance

*Codominance

*Dominance and Phenotype

*Maybe recessive at organismal level, but codominant at molecular level

*Ex. Tay Sachs

*Multiple alleles

*Blood types

*Pleiotropy

*Genes may have multiple phenotypic effects

*Ex. Sickle cells, cystic fibrosis

*Epistasis

*A gene at one locus affects a gene at another locus

*Ex. Labrador retrievers p 217

*Polygenic inheritance

*Many genes involved

*Ex. Human skin color and height

*Nature and Nuture

*Multifactorial-may include genetic and environmental factors

*Ex. Heart disease, diabetes, cancer, alcholism, mental illnesses

*Pedigrees

*consanguineous

*To wed a cousin or not to wed, that is the question…

*Recessive disorders

*Albinism

*Cystic fibrosis 1/2500 of European descent (4% are carriers)

*Sickle Cell Anemia (1/400 African Americans) (2 allelesfull blown, but organismal level-incompletely dominant; heterozygotes have sickle trait-but may have trouble when oxygen low; molecularcodominant)

*Dominant Disorders

*Huntington’s Choreahttp://www.youtube.com/watch?v=65xf1olEpQM

*Achondroplasia

*Polydactyly

*Chromosome theory of

Inheritance

*Sutton, Boveri, et.al

*Mendelian genes have specific loci along chromosomes, and it is the chromosomes that undergo segregation and independent assortment

*Thomas Hunt Morgan

*Fly guy-Drosophila melanogaster

*Great experimental organism

*Small, large # of offspring, short life span, 8 chromosomes, easily observed traits

Phenotype most commonly observed in natural populations~wild type; alternatives~mutant phenotypes

Invented notation – use letter of first mutant discovered and wild is indicated with +

So, red eyes are dominant and the wild type: w+

White eyes were first mutant: w

*Sex-linked traits

*Sex chromosomes

*SRY-sex determining region of the Y

*Y-linked

*X-linked

*Sex linked recessive pedigree

*Sex Linked disorders

*Males can’t be carriers

*Males get it from Mom

*Males have it more often

*Color blindness

*Hemophilia-Royal disease (Queen Victoria)

*Duchenne muscular dystrophy

*X inactivation in Female Mammals

*One of the X chromosomes is inactivated in embryonic development

*Barr Body (Mary Lyon found it is random)-leads to a mosaic

*Tortoiseshell cat

*How X is inactivated

*Attach methyl groups to DNA

*On one X, XIST (X-inactive specific transcript) becomes activemakes RNA product that attaches to one andBarr body

*Linked genes

*http://www.youtube.com/watch?v=-_UcDhzjOio

*Aneuploidy

*Abnormal chromosome number

*Nondisjunction in anaphase I or II

*Monosomy

*Trisomy

*Polyploid

*Down syndrome

*Klinefelter

*Turner

*Alterations in chromosome

structure

*Deletion

*Duplication

*Inversion

*Translocation

*Disorders

*Cri du chat deletion of part of #5

*CML- chronic myelogenous leukemia reciprocal translocation between #9 and #22-shortened 22Philadelphia chromosome

*Genomic imprinting

*Angelmans syndrome http://www.angelman.org/understanding-as/diagnosis/

*Prader-Willi’s syndromehttp://www.youtube.com/watch?v=-6nzi5Rc4wY

*Decade of the genome: http://www.youtube.com/watch?v=Fgq-XoyorWY

*Hemophilia –the royal disease: http://www.youtube.com/watch?v=bmQwMllhCUM

*Other disorders: http://www.youtube.com/watch?v=l0dDhKFk2HU&list=PL199EFC951657FAA4&index=4

*Williams syndrome

http://www.youtube.com/watch?v=gF4DiqEdN3w

http://www.jeansforgenesday.org/disorders/childrensfilms