Nondisjunction/Genetic Disorders Flashcards
take a guess lol
What is Nondisjunction?
Nondisjunction is when a chromosome does not split properly during Anaphase (either I or II). This usually result in an abnormal number of chromosomes in a cell.
What does Nondisjunction result in?
It results in a gamete cell having either too many or too few chromosomes. Because of this, it can result in genetic disorders.
What is the ‘normal’ state of a complete fertilized gamete cell?
A gamete cell that has completed Meiosis has a DNA which is Diploid. Each chromosome has a homologous pair (an exact copy)
What is Trisomy?
Trisomy is when their are 3 copies of a chromosome in 1 cell.
What is Monosomy?
Monosomy is when their is only 1 chromosome in a cell :(
What chromosome does Down Syndrome affect?
Down Syndrome typically affects ‘Chromosome #21’. It is a Trisomy of that specific chromosome.
What are some of the traits that could be observed as a result of Down Syndrome?
You could always identify Down syndrome via it’s characteristic facial features. Down syndrome also features physical growth delays and mild to moderate intellectual disabilities.
Because of this, people diagnosed with it tend to have a shorter life expectancy. It occurs in roughly every 1 out of 600 people.
What is Turner Syndrome?
Turner Syndrome is a Monosomy of the X chromosome. It is a syndrome where individuals appear female but do not sexually develop. It only occurs in females.
Around 1 in 3000 babies get Turner syndrome but unfortunately many of these pregnancies result in a miscarriage.
What is Kleinfelter syndrome?
Kleinfelter syndrome is when a male has THREE sex chromosomes (XXy). Basically a boy is born but they sexually develop with abnormally high amounts of Estrogen. Because of this, they are sterile.
It affects roughly 1 in 500 males.
What are Autosomes?
They are the other 22 chromosomes (aside from the pair of sex chromosomes).
What is a karyotype?
A karyotype is a photograph of the number and appearance of a chromosome.
