Chromosomal Abnormalities Flashcards
During disjunction, chromatids fail to
seperate
In meiosis one, disjunction means that what fails to seperate?
homologous chromosomes
During disjunction in meiosis two, what fails to seperate?
Sister chromatids
What are autosomes?
the other 22 chromosomes
Is disjunction fatal?
Yes (in most cases)
During x inactivation
one of the x chromosomes is turned off
What are inactivated x chromosomes called?
Barr bodies
What is it called when there are three copies of a chromosome?
A trisomy
What important gene is found on the Y chromosome?
SRY gene
What trisomy causes Down Syndrome?
Trisomy 21
What is the result of deletion?
Missing genes (only one copy)
What is the result of duplication?
Extra genes
What is the result of inversion?
Could be normal, could have trouble with meiosis
