Loci and the Human Karyotype Honors Biology Unit

Chromosomes Karyotype: ◦ ordered display of an individual’s chromosomes. ◦ Collection of chromosomes from mitotic cells. ◦ Staining can reveal visible band patterns, gross anomalies.

Meiosis KM 3 Karyotyping

Karyotypes arrange chromosomes in order by size: Largest to smallest

Chromosomes Some large like #1 Some small like #22

Homologous pairs Same Length Centromere in same location Same bands (genes)

Centromere Position The centromere is not exactly in the center of the chromosome “p” arm: (p=petite) the shorter arm of the chromosome “q” arm: the longer arm of the chromosome

Locus (plural=loci) The position that a given gene occupies on a chromosome. (Its like an address for your genes) Written like this: 15p23

Example: 15p23=Chrom 15 small arm, 23 rd band from the centromere

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 2 Skin Color Polygenic 2p18 2q21 S = Dark s= Light SSSS= Dark SSSs= Fairly Dark SSss= Olive Ssss = Light Olive ssss = Lightest White Ssss Lt Olive s sS s

Chrom # Gene Description LocusAlleleMy Geno. My Pheno AA=Lots Aa=some aa= none A=Acne a=No Acne 4p20 Acne Polygenic Incomplete Dominance 4AaSome Acne Aa

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 4Cleft Chin Regular Dominance 4p19 N = Cleft n= no cleft nn No Cleft nn

Chrom # Gene Description LocusAlleleMy Geno. My Pheno Eye color polygenetic Incomplete Dominance 7 & (15) 7p15 B=Brown b=Blue BB=Brown Bb=Light Brown, Hazel, Green bb=blue Bb Light Brown Bb

Chrom # Gene Description LocusAlleleMy Geno. My Pheno Hair Color Incomplete Dominance 7 7p11 H=Brown/Black h=blonde HH=Brown/Black Hh=Light Brown hh=Blonde Hh Light Brown Hh

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 7Cystic Fibrosis Autosomal recessive 7q25 F = No CF f = CF FF No CF F F

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 7 Acne Polygenic Incomplete Dominance 7q11 A= Acne a = no Acne Aa Some acne Aa

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 9 Blood Type A & B Codom. O=Recessive 9q34 I A =A I B =B i=O ii o ii

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 9Rh Factor Normal Dominance 9q30 R = +Rh r = - Rh RrRh+ Rr

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 12 Freckles Normal Dominance 12p5 F = Freckles f= no freckles ff No Freckles f f

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 12 Hair Type Incomplete Dominance 12q24 CC= Curly cc = Straight Cc=Wavy cc Straight C C

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 15 Tay-Sachs Autosomal recessive 15q23 T = No TS t = TS TT No TS T T

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 16Dimples Normal Dominance 16p10 D=Dimples d = No Dimples Dd Dimples Dd

Chrom # Gene Description LocusAlleleMy Geno. My Pheno 23Color Blind Hemophilia B= Not Colorblind b = Colorblind B A A= No Hemophilia a = Hemophilia XBYXAYXBYXAY