Genetics exam 3 questions and answers

karyotyping - ANSWER--Chromosomes prepared from actively dividing cells -Halted in metaphase -Chromosomes arranged according to size -use WBC -stained with Giemsa stain -goes from largest to smallest aneuploidy - ANSWER-Abnormal number of chromosomes. -missing or extra -Ex; Turner's syndrome, Down Syndrome -2n+ =7 -45, XO polyploidy - ANSWER-condition in which an organism has extra sets of chromosomes -3n, 4n, 5n, etc. -3n=9 Primary down syndrome - ANSWER--Trisomy 21 (three copies of chromosome 21) -nondisjunction during meiosis from a parent -47, XY, +21 familial down syndrome - ANSWER-Caused by a Robertsonian translocation in which the long arm of chromosome 21 is translocated to another chromosome; tends to run in families. -45, XX, -21, -14, +t( 14, 21) -phenotypically normal because same amount of chromosomes Duplication - ANSWER--tandem; next to each other -displaced; further away -reversed; CDEFFEG -can have both -produce 2x amount in each cell Deletion - ANSWER-A change to a chromosome in which a fragment of the chromosome is r