Deck 7: Human Birth Defects

Question 1

________ The most common numerical autosomal abnormality

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Answer 1

D
Trisomy 21 is the most common type of numerical autosomal abnormality,occurring about once in 600 neonates.The cause of the chromosomal abnormality (trisomy of chromosome 21)is nondisjunction during oogenesis,usually in older mothers.About 4% of people with Down syndrome have the extra 21 chromosome attached to another chromosome (usually number 14).

Question 2

________ Mental deficiency (retardation),low-set ears,and early postnatal death

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Answer 2

C
Infants with trisomy 18 have multiple major anomalies.Like those with the less common trisomy 13 syndrome,these infants have a severe mental defect and die during early infancy.Trisomy 18 is much more severe than Down syndrome,and females are more often affected (about 78% of these infants are female).

Question 3

________ Normal female appearance and usually fertile

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Answer 3

A
Most females with the triple X chromosome abnormality appear normal and are fertile.These women have two sex chromatin masses in their cells because of the presence of the extra X chromosome.Some triple X females have borne children,all of whom are normal and have normal karyotypes.Most females with four or more X chromosomes are also physically normal but severely retarded.

Question 4

________ Potent teratogen that affects limb development

A)Cytomegalovirus
B)Androgenic agents
C)Thalidomide
D)Toxoplasma gondii
E)Aminopterin

Question 5

________ Mother may be infected with it by eating poorly cooked meat

A)Cytomegalovirus
B)Androgenic agents
C)Thalidomide
D)Toxoplasma gondii
E)Aminopterin

Question 6

________ May cause masculinization of female fetuses

A)Cytomegalovirus
B)Androgenic agents
C)Thalidomide
D)Toxoplasma gondii
E)Aminopterin

Question 7

________ Sterile male with chromatin-positive nuclei

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Question 8

________ Strong association with late maternal age

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Question 9

________ Mental retardation,simian crease,and heart defect

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Question 10

________ Female with chromatin-negative nuclei

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Question 11

________ Webbed neck and short stature

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY

Question 12

________ Intracellular parasite often found in cats

A)Cytomegalovirus
B)Androgenic agents
C)Thalidomide
D)Toxoplasma gondii
E)Aminopterin

Question 13

________ Antitumor agent and potent teratogen

A)Cytomegalovirus
B)Androgenic agents
C)Thalidomide
D)Toxoplasma gondii
E)Aminopterin

Question 14

________ Small testes and hyalinization of the seminiferous tubules

A)47, XXX
B)45, XO
C)Trisomy 18
D)Trisomy 21
E)47, XXY