Dosage Compensation and Nondisjunction

Question 1

Nondisjunction

Answer 1

Failure of chromosomes to segregate properly (either homologous pairs in
anaphase I or sister chromatids in anaphase II)

Question 2

Aneuploidy

Answer 2

an abnormal number of chromosome

Question 3

Dosage Compenstaion

Question 4

Turner Syndrome: XO

Answer 4

45 chromosomes: XO
* Arises from gamete produced with no sex
chromosome due to nondisjunction

Question 5

Klinefelter Syndrome

Answer 5

47+ chromosomes: XXY, XXXY, XXXXY
* Arises from gamete produced with extra sex
chromosome(s) due to nondisjunction
* variation in X chromosome number possible with
dosage compensation

Question 6

Poly X Female

Answer 6

47+ chromosomes: XXX, XXXX, XXXXX
* Arises from gamete produced with extra sex
chromosome(s) due to nondisjunction
* variation in X chromosome number possible with
dosage compensation

Question 7

Barr Bodies

Answer 7

an inactive x chromosome
- number of x chromosomes minus 1

Question 8

Homozygotes

Answer 8

XBXB / XbXb (females)

Question 9

Hemizygotes

Answer 9

XBY / XbY (Males)

Question 10

Heterozygote

Answer 10

XBXb (Female Calico)