Chromosomal Abnormalities

Question 1

Abnormal chromosomes account for at least ____ of spontaneous abortions.

Answer 1

50%

Question 2

Aneuploidy

Answer 2

extra or missing chromosome

Question 3

More likely to have an ____ chromosome than a _____ chromosome.

Answer 3

Extra, missing

Question 4

Trisomy

Answer 4

one extra chromosome

Question 5

Monosomy

Answer 5

one absent chromosome

Question 6

Polyploidy

Answer 6

extra chromosome sets

Question 7

Deletion

Answer 7

part of a chromosome missing

Question 8

Duplication

Answer 8

part of a chromosome present twice

Question 9

Translocation

Answer 9

two chromosomes join long arms or exchange parts

Question 10

Inversion

Answer 10

segment of chromosome reversed

Question 11

Isochromosome

Answer 11

a chromosome with identical arms

Question 12

Ring chromosome

Answer 12

a chromosome that forms a ring due to deletions in telomeres, which cause ends to adhere

Question 13

Triploid (3n)

Answer 13

a polyploidy that has three sets of chromosomes

Question 14

Nondisjunction

Answer 14

meiotic error that causes aneuploidy

Question 15

Nondisjunction in meiosis 1 results in…

Answer 15

copies of both homologs in one gamete

Question 16

Nondisjunction in meiosis 2 results in…

Answer 16

both sister chromatids in one gamete

Question 17

Mosaic

Answer 17

individual with two chromosomally-distinct cell populations

Question 18

Trisomies

Answer 18

autosomal aneuploids, there are 3 different kinds

Question 19

Trisomy 21

Answer 19

down syndrome
-most common among newborns
-distinct facial and physical problems

Question 20

Trisomy 18

Answer 20

Edwards syndrome
- muscle issues, closed fist, don’t survive

Question 21

Trisomy 13

Answer 21

Patau syndrome
- distinct feature= eye fusion
-don’t survive past 6 months

Question 22

______ leads to sex chromosome aneuploids.

Answer 22

nondisjunction

Question 23

Turner(XO) Syndrome

Answer 23

-45, X
- female
-99% effected in utero will die
-sexual maturity impaired
- can’t visualize in 3D

Question 24

Triplo-X syndrome

Answer 24

47, XXX
-female
-tallness, menstrual irregularities, and slight impact on intelligence

Question 25

Klinefelter syndrome

Answer 25

47, XXY -male - common cause of male infertility bc of incomplete sexual development - long limbs, large hands and feet

Question 26

XXYY syndrome

Answer 26

-male -AAD, OCD, learning disabilities -infertile

Question 27

Jacobs symdrome

Answer 27

47, XYY -male -phenotypically normal -great height, acne, speech and reading disabilities

Question 28

Deletions are often ___ inherited.

Answer 28

not

Question 29

Cri-du-chat (cat cry) syndrome

Answer 29

deletion 5p

Question 30

Duplications often ____ inherited.

Answer 30

not

Question 31

Large duplications tend to have an ________, while smaller ones _____.

Answer 31

effect, do not

Question 32

2 types of translocation

Answer 32

Robertsonian and reciprocal

Question 33

Robertsonian translocation

Answer 33

two homologous acrocentric chromosomes break at the centromere and their long arms fuse

Question 34

How many chromosomes do translocation carriers have?

Answer 34

45

Question 35

Translocation down syndrome

Answer 35

5% of down syndrome results from Robertsonian translocation - one parent must be a translocation carrier

Question 36

Reciprocal translocation

Answer 36

Two non-homologous chromosomes exchange parts

Question 37

Inversion example

Answer 37

ABCdefG ABCfedG

Question 38

Paracentric inversion

Answer 38

inverted region DOES NOT include centromere

Question 39

Pericentric inversion

Answer 39

inverted region DOES include centromere

Question 40

Isochromosomes form when...

Answer 40

centromeres divide along incorrect plane during meiosis

Question 41

Acrocentric

Answer 41

centromere is really far to one side