Abnormal Numbers of Chromosomes Flashcards
What does aneuploid refer to?
Having an abnormal number of chromosomes
What is monosomy?
Having only one version of a particular chromosome instead of 2.
Monosomy is lethal in all cases except when what is involved?
Sex chromosomes
What disorder is an example of monosomy?
Turner Syndrome
What is trisomy?
Having three versions of a particular chromosome instead of two
What is an example of trisomy?
Down Syndrome
What is a karyotype?
An enlarged micrograph depicting a person’s chromosomes organized by type (did one of these in lab)
What is nondisjunction?
failure of paired chromosomes to separate during cell division
What causes most cases of aneuploidy?
Nondisjunction
An extra copy of which chromosome causes Down Syndrome?
Chromosome 21
Chances of Down Syndrome are directly related to what factor?
The mother’s age
What is Turner Syndrome?
A case of aneuploid when a female is born with only 1 X chromosome
Females born with Turner Syndrome are normally what ____
sterile; lack secondary sex characteristics
What is Klinefelter Syndrome?
A case of aneuploid where a male is born with two or more X chromosomes instead of 1.
Males born with Klinefelter Syndrome are normally ____
sterile; lack secondary sex characteristics
