Nondisjunction Disorders

Question 1

extra chromosome number 21.

Answer 1

Down Syndrome: Trisomy 21

Question 2

Edwards Syndrome: Trisomy of chromosome 18

Answer 2

• may have heart defects and abnormalities of other organs. small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers.

Question 3

Patau Syndrome: Trisomy of chromosome 13

Answer 3

serious eye, brain, circulatory defects as well as cleft palate

Question 4

Turner Syndrome

Answer 4

• monosomic disorder that produces a female with a single X chromosome

Question 5

Klinefelter Syndrome

Answer 5

• is caused by either the sperm or egg with 2 chromosomes
• child inherits two X chromosomes and a single Y chromosome
  appears to be a male at birth
• at sexual maturity, he begins
  producing high levels of female sex
  hormones
  sterile

Question 6

Triple X Syndrome or Trisomy X

Answer 6

• additional X chromosome in each of a female’s cells.
• an increased risk of learning disabilities and delayed

Question 7

XYY Syndrome

Answer 7

• extra copy of the Y chromosome in each of a male’s cells.
• typically causes no unusual physical features.