10.4 Flashcards
Nondisjunction
Chromosomes don’t separate correctly in meiosis
Trisomy
3 copies of 1 chromosome
2n-1 in one cell
Monosomy
An extra copy of a chromosome
2n+1 in one cell
Autosomes
Not a sex chromosome
Sex chromosomes
A chromosome that determines sex
Barr body
Inactive X chromosome
Deletion
Stuff is deleted
Inversion
a piece of DNA in a chromosome gets reversed – meaning it is in the right place in the right chromosome, but the wrong way round
Translocation
A genetic change in which a piece of one chromosome breaks off and attaches to another chromosome. Sometimes pieces from two different chromosomes will trade places with each other.
How nondisjunction leads to incorrect number of chromosomes
There are more numbers of chromosomes in a gamate or cell than normal
What determines human biological sex at birth
The x and y sex chromosomes
What happens to a zygote for each type of chromosomal abnormality (deletion, duplication, inversion, translocation)
They normally do not survive
Determine the type of reproductive system (male or female) and the number of Barr bodies produced per cell for a given set of sex chromosomes
If they have X and a bar body then they are female. If they have X Y then they are male
Analyze an individual chromosome to determine the type of chromosomal abnormality that occurred (deletion, duplication, inversion, translocation, nondisjunction)
Look at it
Analyze a karyotype to determine the type of chromosomal abnormality that occurred (deletion, duplication, inversion, translocation, nondisjunction)
Look at it
