Deck 6: Genetic and Developmental Disorders

Question 1

Information parents should be given about the consequences of PKU includes

A) high dietary phenylalanine may help induce enzyme production.
B) PKU is commonly associated with other congenital anomalies.
C) failure to avoid phenylalanine results in progressive mental retardation.
D) mental retardation is inevitable.

Answer 1

failure to avoid phenylalanine results in progressive mental retardation.

Question 2

Characteristics of X-linked (sex-linked)recessive disorders include

A) all daughters of affected fathers' being carriers.
B) boys' and girls' being equally affected.
C) the son of a carrier female's having a 25% chance of being affected.
D) affected fathers' transmitting the gene to all their sons.

Answer 2

all daughters of affected fathers' being carriers.

Question 3

Characteristics of Marfan syndrome include that it (Select all that apply.)

A) is a single-gene disorder.
B) involves alterations in connective tissue.
C) leads to skeletal and joint deformities.
D) leads to short stocky build.
E) results in dangerous cardiovascular disorders.

Answer 3

is a single-gene disorder.
involves alterations in connective tissue.
leads to skeletal and joint deformities.
results in dangerous cardiovascular disorders.

Question 4

Huntington disease primarily affects the _____ system.

A) neurologic
B) muscular
C) gastrointestinal
D) endocrine

Question 5

The primary factor associated with the risk of Down syndrome is

A) family history of heritable diseases.
B) exposure to TORCH syndrome organisms.
C) maternal alcohol intake.
D) maternal age.

Question 6

A fetus is most vulnerable to environmental teratogens during

A) birth.
B) conception.
C) the first trimester.
D) the last trimester.

Question 7

Children with PKU must avoid phenylalanine in the diet.Phenylalanine is most likely to be a component of

A) fat.
B) sugar.
C) protein.
D) carbohydrate.

Question 8

Huntington disease is often transferred to offspring before a parent knows of the genetic possibility of this disease,because

A) symptoms are so mild that they are not recognized.
B) symptoms often do not occur until approximately 40 years of age.
C) genetic testing for the disease is not possible.
D) the genetic alteration is rarely expressed.

Question 9

The risk period for maternal rubella infection leading to congenital problems begins

A) prior to conception.
B) during the last trimester.
C) at birth.
D) all through pregnancy.

Question 10

A point mutation

A) results from the addition or loss of one or more bases.
B) is because of the translocation of a chromosomal segment.
C) always produces significant dysfunction.
D) involves the substitution of a single base pair.

Question 11

Males are more likely than females to be affected by ________ disorders.

A) X-linked
B) autosomal-dominant
C) autosomal-recessive
D) chromosomal nondisjunction

Question 12

The parents of a child with PKU are concerned about the risk of transmitting the disorder in future pregnancies.The correct assessment of the risk is

A) each child has a 25% chance of being a carrier.
B) each child has a 25% chance of being affected.
C) since one child is already affected, the next three children will be unaffected.
D) one cannot predict the risk for future pregnancies.

Question 13

Results of biochemical tests indicate an infant has phenylketonuria (PKU).The parents ask what PKU means.Correct responses would include all the following except PKU

A) is an enzyme deficiency resulting in the inability to metabolize phenylalanine.
B) is an inborn error of metabolism.
C) results from a chromosome abnormality called nondisjunction.
D) is transmitted as an autosomal-recessive disorder.

Question 14

Cystic fibrosis is a single-gene disorder that primarily affects

A) brain and heart.
B) kidney and adrenals.
C) lungs and pancreas.
D) liver and intestine.