Human Genetics and Disorders Flashcards
(38 cards)
Human Chromosome Disorders Some have
high frequency in humans then in others
the high frequency of human chromosomes disorders lead to
most embryos to be spontaneously aborted
due to biochemical imbalance
it causes developmental problems
Survivable
upsets the balance less
syndrome
characteristic set of symptoms
Nondisjunction
chromosomes don’t separate properly during meiosis
Chromosomal Mutations names
deletion
duplication
inversion
translocation
deletion
loss of a chromosomal segment
duplication
repeat a segment
inversion
reverses a segment
translocation
move segment from one chromosome to a non-homologous chromosome
in nondisjunction homologous chromosomes
do not separate properly during Meiosis 1
in nondisjunction sister chromatids
fail to separate during Meiosis 2
aneuploidy
too many or too few chromosomes
cause of aneuploidy
trisomy and monosomy
trisomy
cells have 3 copies of a chromosome
monosomy
cells have only 1 copy of a chromosome
karyotype
A complete set of chromosomes from a cell that has been photographed during cell division and arranged in a standard sequence.
trisomy 21 aka
down syndrome
trisomy 21
3 copies of chromosome 21
Chromosome 21 is the
smallest chromosome and has severe affects
Frequency of Down
syndrome correlates
with the
age of the mother
as the mother gets older there is a bigger chance a offspring will have down syndrome
more humans are tolerant to
sex chromosomes abnormality
either there missing them or have to many
XXY
Klinefelter’s syndrome male