Applied - N16

Question 1

Aneuploidy

Answer 1

abnormal number of certain chromosomes

Question 2

Karyotype and how to make it

Answer 2

organized display of homologous chromosomes and sex chromosomes (46 total)
- sample blood
- add blood to phytohemagglutinin
- incubate for 2-3 days
- add colcemid, culture 1-2 hours
- transfer to tube, centrifuge, add low salt solution to eliminate RBCs
- stain slide for microscope and examine

Question 3

Amniocentesis & Chorionic Villus sampling

Answer 3

Amnio: withdraw amniotic fluid in 14th - 16th week of pregnancy, results take several weeks
CVS: chorionic villus tissue sample in 8th - 10th week, results take about a day

Question 4

Sex chromosome alterations

Answer 4

Klinefelter (XXY): trisomy, tall, poor beard growth, breast development, female pubic hair pattern, small testes + sterile

Turner syndrome (XO): monosomy, short, webbed neck, broad chest, internal sex organs do not mature, sterile, aorta constriction

Triple X syndrome (XXX): typically normal phenotype and fertile

Jacobs syndrome (XYY): much taller than average, normal fertility

Question 5

Trisomy

Answer 5

type of aneuploidy where individual has 3 of one type of chromosome

Question 6

Down syndrome

Answer 6

Autosomal alteration: caused by 3 copies of (trisomy) chromosome 21
- pronounced crease on palm of hand

Question 7

Patau syndrom

Answer 7

Autosomal alteration: caused by 3 copies of (trisomy) chromosome 13
- severely mentally challenged
- cleft palate
- deaf
- malformed organs

Question 8

Edwards syndrome

Answer 8

trisomy of chromosome 18
- small newborns
- low set ears, webbed neck, receding chin, prominent back of skull
- organ malformations

Question 9

what can increase frequency of aneuploid defect?

Answer 9

pregnancy at older age