Unformatted text preview: BIO 311D LECTURE 6 GENETICS sex-linked disorders and chromosomal abnormalities 1/29/07 Sex-linked genes 44 + XY Parents 44 + XX 22 + X Sperm 22 + Y Ova 22 + X 44 + XX Zygotes (offspring) 44 + XY (a) The X-Y system 22 + XX 22 + X (b) The X0 system
76 + ZW 76 + ZZ (c) The ZW system
(Haploid) (d) The haplo-diploid system X inactivation Two cell populations in adult cat: Active X Early embryo: X chromosomes Cell division Inactive X and X chromosome Inactive X inactivation Orange fur Black fur Allele for black fur Active X Human X-inactivation Chromosome disorders Aneuploidy - Down syndrome Trisomy 21 Turner syndrome Monosomy X, so XO producing an X0 karyotype XYY XXX Klinefelter syndrome - XXY Testicular feminization Dominance and recessiveness in human traits
Left vs right thumb on top when hands clasped: L_ vs ll Tongue roller vs nonroller: R_ vs rr Little finger straight vs bent towards ring finger: S_ vs ss Hair present vs absent on middle of any finger: H_ vs hh Free vs. attached earlobes: F_ vs ff Dimples, dominant Cleft chin, dominant Longer second toe is dominant Straight thumb is dominant DOMINANT TRAITS eye coloring vision brown eyes farsightedness normal vision normal vision normal vision dark hair non-red hair curly hair full head of hair widow's peak dimples unattached earlobes freckles broad lips immunity to poison ivy normal pigmented skin normal blood clotting normal hearing normal hearing and speaking RECESSIVE TRAITS grey, green, hazel, blue eyes normal vision nearsightedness night blindness color blindness* blonde, light, red hair red hair straight hair baldness* normal hairline no dimples attached earlobes no freckles thin lips susceptibility to poison ivy albinism hemophilia* congenital deafness deaf mutism hair facial features other Implications of heritability... Next time...
The Hardy-Weinberg Theorem Ch. 23 ...
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