PCB 3063 exam 2 Questions and Answers Fully Solved Latest Update

PCB 3063 exam 2 Questions and Answers Fully Solved Latest Update aromatase - Answers converts androgens to estrogens in temp dependent sex determination PARs - Answers on each end of y chromosome; synapse and recombine w X chromosomes in meiosis MSY - Answers male specific region of Y, middle section including SRY SRY - Answers sex determining region Y; controls sexual development, codes for testis-determining factor (TDF) Males w two X chromosomes and no Y? - Answers one X contains SRY females with one X and one Y? - Answers Y chromosome missing SRY TDF - Answers testes determining factor, on SRY, transcription factor Klinefelter syndrome - Answers More than 1 X chromie, (XXY) usually male, infertile, 47 XXY, Karyotype 47, XXX Syndrome (Triplo-X) - Answers (XXX) female differentiation, usually perfectly normal, also possible tetra and penta X, bc of nondisjunction during meiosis Turner Syndrome - Answers 45, X0, female genitalia, short, skin flaps on back of neck, underdeveloped, normal intelligence, bc nondisjunction during meiosis dosage compensation - Answers Mechanism in which X chromosome inactivation equalizes gene expression between males and females; deletion of extra genes when 2+ x chromosomes are present x:y chromosome ration for male drosophila - Answers 0.5 x:y chromosome ration for metamale drosophila - Answers 0.33 x:y chromosome ration for female drosophila - Answers 1.0 x:y chromosome ration for metafemale drosophila - Answers 1.5 x:y chromosome ration for intersex drosophila - Answers .75-.67 Barr body - Answers Inactivated X chromosome Lyon hypothesis - Answers the proposal that dosage compensation in mammalian females is accomplished by partially and randomly inactivating one of the two X chromosome; why female cats can have random spots of different colors mechanism of x inactivation - Answers DNA and/or histone proteins are chemically modified mechanism of x inactivation - Answers DNA inactivated by splices in the genome imprinting - Answers process whereby expression of genes on one homolog but the other in unaffected Xic (X inactivation center) - Answers Contains several genes important for X inactivation XIST (X inactive specific transcript) - Answers gene on Xic, critical for gene inactivation possible explanations for conditions of people with abnormal numbers of sex chromosomes - Answers - inactivation doesn't take place early enough - not all x chromosomes are inactivated aneuploidy - Answers the presence of an abnormal number of chromosomes in a cell but not a complete set monosomy - Answers loss of a single chromosome from a diploid gene trisomy - Answers gain of a single chromosome from diploid genome euploidy - Answers complete haploid sent of chromosomes are present