The basic components of DNA are:
a phosphate molecule, deoxyribose, and four nitrogenous bases.
Which of the following mutations have the most significant effect on protein synthesis?
Frameshift mutations
The base components of DNA are:
A, G, C, and T
A DNA strand has a region with the sequence ATCGGATC. Which of the following would be a complementary strand?
TAGCCTAG
The process by which RNA directs the synthesis of protein is called:
translation.
An error in which homologous chromosomes fail to separate during meiosis is termed:
nondisjunction.
A somatic cell that does not contain a multiple of 23 chromosomes is called:
a diploid cell, and/or a aneuploid cell.
A 20-year-old pregnant female gives birth to a stillborn child. Autopsy reveals that the fetus has 92 chromosomes. Which of the following describes this condition?
Tetraploidy
The condition in which an extra portion of a chromosome is present in each cell is called:
partial trisomy
If a person is a chromosomal mosaic, the person may:
have a mild form of the genetic disease.
The most common cause of Down syndrome is:
maternal nondisjunction.
Risk factors for Down syndrome include:
pregnancy in women over age 35.
A 13-year-old girl has a karyotype that reveals an absent homologous X chromosome with only a single X chromosome present. Her condition is called:
Turner syndrome.
An XXY person has the genetic disorder called:
Klinefelter syndrome.
Which of the following genetic disorders results in severe mental retardation caused by a deletion of part of chromosome 5?
Cri du chat syndrome
A couple has three offspring: one child with an autosomal dominant disease trait and two who are normal. The father is affected by the autosomal dominant disease, but the mother does not have the disease gene. What is the recurrence risk of this autosomal
50%
People who have neurofibromatosis will show varying degrees of the disease; this is because of the genetic principle of:
expressivity.
Cystic fibrosis is caused by an _____ gene.
autosomal recessive
A 15-year-old female is diagnosed with Prader-Willi syndrome. This condition is an example of:
gene imprinting.
Joey, age 9, is admitted to a pediatric unit with Duchenne muscular dystrophy. He inherited this condition through a:
sex-linked recessive trait.
A child is born with blue eyes (bb). The child's mother has blue eyes and the father has brown eyes. Which of the following represents the father?
Bb
A child is diagnosed with cystic fibrosis. History reveals that the child's parents are siblings. Cystic fibrosis was most likely the result of:
consanguinity.
A 12-year-old male is diagnosed with Klinefelter syndrome. His karyotype would reveal which of the following?
XXY
To express a polygenic trait:
several genes must act together.
What is the diagnosis of a 13-year-old female who has a karyotype that reveals an absent homologous X chromosome with only a single X chromosome present? Her features include a short stature, widely spaced nipples, reduced carrying angle at the elbow, and
Turner syndrome
A normal male and a female carrier for red-green color blindness mate. Given that red-green color blindness is an X-linked recessive trait, what is the likelihood of their children being affected?
All males, no females
The gradual increase in height among the human population over the past 100 years is an example of:
multifactorial trait.
When considering how nitrogenous bases pair to form a double helix, which of the following pairs occur most often?
Cytosine�Guanine
The protein most important for DNA replication is:
DNA polymerase.
The regions of the heterogeneous nuclear RNA that must be spliced out to form functional RNA are called:
introns.
A 5-year-old male presents with mental retardation and is diagnosed with Fragile X syndrome. Which of the following is most likely to cause this syndrome?
Duplication at fragile sites
The person that a pedigree chart begins with is called the:
proband.
A 50-year-old male was recently diagnosed with Huntington disease. Transmission of this disease is associated with:
delayed age of onset.