Final Exam - Chromosomal Abberations Flashcards
nondisjunction
during cell divison or chromatids dail to properly seperate in mitosis, meiosis I or meiosis II
- results in organisms mosaic phenotype
- error in gamete causes whole organism to be erred
monosomy
-lack of one chromosome which are lethal
Trisomy
-addition of a chromosome
-generally lethal or spontanelously abort
ex
-trisomy 13/18 Pateau and Edwards birth but die
-Trisomy 21 -Down’s syndorme
Klinefelter’s syndrome
- XXY
- breast tissue development, testes not fully developed, lower IQ
Turner’s Syndrome
XO
-female, shorter, undifferentiated gonads, ovarian streaks dont turn into ovary, doesnt make estrogen or progestorone so remains pre pubesent
Jacob’s syndrome
- XYY
- taller, lower IQ,
Poly - X
XXX
-spaital relationship problems, not really significant
Polyploid
- any abnormal multiple of N
- generally spontaneously abort, if birthed they will die shortly after birth
- 69-triploid
- 92 tetrapolid
deletion
loss of a cs piece which may involve a fragile site where DNA is not structured
-causes Cri du chat or prader willi and angelman’s
imprinting
genes are expressed in a parent-of-origin-specific manner. If the allele inherited from the father is imprinted, it is thereby silenced, and only the allele from the mother is expressed.
duplication
trinucleotide repeats
-huntington’s
inversion
no loss or gain of genetic material on cs or in cell
- can lead to loss of gene control as genes cannot interact normally which causes cancer
- cs breaks and sticks back together the wrong way
translocation
- exchange of genetic material between 2 nonhomologous chromosomes
- reciprocal- swapping
- nonreciprocal-one gives up a piece and another recieves
- Robersonian-generally involves loss of 2 p arms and fusion of 2 nonhomologous q arms so a form of down’s syndrome occurs
uniparental disomy
compensating and imprinting errors of S and N or U genes
- prader willi
- angelman
- rare cystic fibrosis
