7.5 Chromosomal Abnormalities Flashcards
What is nondisjunction?
Nondisjunction is when chromosomes fail to separate, and leave some gametes with an abnormal amount of chromosomes.
How many of each chromosome should a normal gamete have?
1
What fails to separate in Meiosis 1?
Homologous chromosomes
What fails to separate in Meiosis 2?
Sister chromatids
What are autosomes?
The first 22 chromosome pairs
What are the sex chromosomes?
The 23rd pair, XX or XY (or abnormalities)
What determines the sex of a baby at birth?
If they have the Y chromosome or not.
What is X chromosome inactivation?
When one of the X chromosomes don’t express themselves and transform into a “barr body”
What is deletion?
When a segment of a chromosome gets completely deleted
What is duplication?
When a segment is doubled
What is translocation?
When a segment of a chromosome is relocated to another chromosome
What is inversion?
When a segment is flipped
