Which of the following statements applies to the sex chromosomes?
A) They are identified as XY in the female.
B) They are numbered pair 23 in the karyotype.
C) They contain the same genes as in the other pairs of chromosomes.
D) They are found only in the cells in the gonads (the ovaries and the testes). - ANSB
What is the term for an arrangement of the chromosomes from an individual's cell, organized in
pairs based on size and shape?
A) Pedigree
B) Punnett squares
C) Karyotype
D) Genotype - ANSC
What is characteristic of a congenital disorder?
A) Genes are not involved.
B) It is strictly a developmental anomaly.
C) A cause is known.
D) It is usually manifested in the neonatal period. - ANSD
What is the probability of two parents, both carriers of a defective recessive gene, producing a
homozygous child (with each pregnancy)?
A) 0%
B) 25%
C) 50%
D) 75% - ANSB
In the case of an X-linked recessive disorder, a carrier mother and unaffected father could
produce a/an:
A) normal female.
B) affected female.
C) male carrier. - ANSA
Down syndrome is an example of a/an:
A) autosomal dominant disorder.
B) multifactorial disorder.
C) developmental defect
D) chromosomal disorder - ANSD
Agents that cause damage during embryonic or fetal development are called:
A) teratogenic.
, B) mutagenic.
C) multifactorial agents.
D) polygenic agents. - ANSA
What is an example of a multifactorial congenital disorder?
A) Type AB blood
B) Down syndrome
C) Color blindness
D) Cleft lip and palate - ANSD
Ultrasonography during pregnancy would be helpful in detecting fetal:
A) enzyme deficits.
B) structural anomalies.
C) chromosomal defects.
D) hormonal abnormalities. - ANSB
Which of the following statements regarding Down syndrome is TRUE?
A) The typical physical characteristics are present at birth.
B) All children with Down syndrome have the same organ defects and medical problems.
C) The extent of cognitive impairment can be assessed at birth.
D) The birth of a child with Down syndrome is only a risk to mothers over age 35. - ANSA
Which of the following statements applies to Huntington's disease?
A) The effects are obvious at birth.
B) There is a test for the defective gene.
C) There is a 50% probability that the child of an affected parent will be a carrier.
D) The child must inherit the defective gene from both parents in order to be affected. - ANSB
A mother is a carrier of Duchenne muscular dystrophy; the father is unaffected. They have one
son with muscular dystrophy. Another male child is expected. The probability of the second son
having muscular dystrophy is:
A) 100%
B) 50%
C) 25%
D) 0% - ANSB
Hemophilia A has been diagnosed in a young boy. He has inherited this defective gene from:
A) his father.
B) his mother.
C) both parents. - ANSB
A father affected with hemophilia A, whose wife is unaffected, will pass on the defective gene to:
A) all of his sons, who will be affected.
B) 50% of his sons, who will be affected.