Question 1

Which of the following statements applies to the sex chromosomes?

Accepted Answer

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).

Question 2

TORCH is an acronym for routine prenatal screening tests for high-risk maternal infections; TORCH stands for:

Accepted Answer

A)  toxoplasmosis, other (hepatitis B, mumps, rubeola, varicella, gonorrhea, syphilis), rubella, cytomegalovirus, and herpes. 
B)  tuberculosis, other (hepatitis B, mumps, rubeola, varicella, gonorrhea, syphilis), rabies, cytomegalovirus, and HIV. 
C)  toxoplasmosis, other (hepatitis B, mumps, rubeola, varicella, gonorrhea, syphilis), rabies, cytomegalovirus, and HIV. 
D)  tuberculosis, other (hepatitis B, mumps, rubeola, varicella, gonorrhea, syphilis), rabies, cytomegalovirus, and herpes.

Question 3

The purpose of the Human Genome Project was to:

Accepted Answer

A)  map the nucleotide sequence and identify the genes on each human chromosome. 
B)  study the common patterns of inheritance of single-gene disorders. 
C)  manipulate the sequence of DNA in microorganisms and animals. 
D)  identify spontaneous alterations in genetic material caused by teratogens.

Question 4

Developmental disorders can result from all the following EXCEPT:

Accepted Answer

A)  exposure to radiation. 
B)  mercury in foods and water. 
C)  drugs and alcohol. 
D)  folic acid.

Question 5

Exposure to cocaine during pregnancy leads to increased risk of:

Accepted Answer

A)  premature birth. 
B)  respiratory problems. 
C)  sudden infant death syndrome. 
D)  A, B, and C

Question 6

Agents that cause damage during embryonic or fetal development are called:

Accepted Answer

A)  teratogenic. 
B)  mutagenic. 
C)  multifactorial agents. 
D)  polygenic agents.

Question 7

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:

Accepted Answer

A)  100% 
B)  50% 
C)  25% 
D)  0%

Question 8

Genes located at the same site on a pair of homologous chromosomes that are also matched for function are called:

Accepted Answer

A)  alleles. 
B)  genotypes. 
C)  autosomes. 
D)  phenotypes.

Question 9

Which of the following statements applies to Huntington's disease?

Accepted Answer

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.

Question 10

When genetic influences combine with environmental factors to cause an abnormality, the result is called a:

Accepted Answer

A)  chromosomal disorder. 
B)  developmental disorder. 
C)  multifactorial disorder. 
D)  single-gene disorder.

Question 11

A spontaneous alteration in genetic material that may result from exposure to harmful substances is termed:

Accepted Answer

A)  autosome. 
B)  genotype. 
C)  meiosis. 
D)  mutation.

Question 12

What is the probability of two parents, both carriers of a defective recessive gene, producing a homozygous child (with each pregnancy)?

Accepted Answer

A)  0% 
B)  25% 
C)  50% 
D)  75%

Exam 21: Congenital and Genetic Disorders