4.4 - nondisjunction

Question 1

nondisjunction occurs when

Answer 1

homologous chromosomes fail to separate during meiosis 1 or meiosis 2

Question 2

trisomy

Answer 2

a chromosomal abnormality in which there are 3 homologous chromosomes instead of a pair of them

Question 3

monosomy

Answer 3

1 homologous chromosome instead of a pair

Question 4

nondisjunction disorders examples

Answer 4

down
turner
klinefelter
patau
edwards
triple x
jacob

Question 5

down syndrome

Answer 5

trisomy (+) 21

Question 6

turner syndrome

Answer 6

monosomy on x chromosome (XO)

Question 7

klinefelter syndrome

Answer 7

trisomy two x and one y

Question 8

patau syndrome

Answer 8

trisomy 13 if female

Question 9

edwards syndrome

Answer 9

trisomy 18 if male

Question 10

3 ways to test for nondisjunction

Answer 10

amniocentesis
CVS (chorionic villus sampling)
multiple marker screening

Question 11

amniocentesis

Answer 11

at 15-20 weeks, cells are obtained from the amniotic sac and a karyotype is prepared

Question 12

CVS

Answer 12

chorionic villus sampling
as early as 8 weeks, cells from the chorion that surround the embryo can be removed to make a karyotype

Question 13

multiple marker screening

Answer 13

blood tests can be done throughout pregnancy to examine proteins and hormones that could indicate a nondisjunction disorder

Question 14

2 assistive reproductive technologies

Answer 14

IVF
IUI

Question 15

IVF

Answer 15

in vitro fertilization
hormones inc egg production
eggs are retrieved and fertilized by sperm in a lab then put back

Question 16

IUI

Answer 16

artificial insemination/intrauterine injection
sperm is inserted directly in reproductive tract to meet the egg when released