Chapter 13: Sex-Linked Traits

MATES Biotechnology, Sprague 2024

who is thomas hunt morgan

studied sex linked traits in fruit flies (wild red vs mutant white)

nondisjunction

• failure of homologues or sister chromosomes to separate properly during meiosis

• causes for a gain or loss of a chromosome called aneuploidy

what are barr bodies

• during embryonic development females have to inactive an X chromosome

• the X chromosome that is repressed is attached to the nucleus while the expressed one shows its phenotype

xxx syndrome in females

• 3 X chromosomes

• symptoms: learning disabilities, developmental delays, tall stature, kidney problems

klinefelter’s syndrome

• X chromosome nondisjunction; males who have an XXY zygote

• symptoms: many female characteristics

turner’s syndrome

• when a female has only one X chromosome with the other partially missing or incomplete

• symptoms: developmental abnormalities of reproductive organs, delayed puberty, short stature, heart problems, high blood pressure, etc.

down syndrome

• additional chromosome

• trisomy in chromosome 21

hemophilia characteristics

• poor blood clotting

• X-linked recessive (common in males)

what is amniocentesis used for

detecting genetic disorders in unborn babies