Florida National University Homozygous Dominant Multiple Choice Questions

0.25 PointsA couple in which the woman is homozygous dominant for clotting ability and the man has hemophilia A will produce:

1. carrier daughters and affected sons.
2. affected daughters and affected sons.
3. carrier daughters and normal sons.
4. normal daughters and normal sons.
5. offspring of unknown genotype for this gene.

0.25 PointsA fragile site:

1. is found only on the X chromosome.
2. occurs in only one of the sister chromatids.
3. is associated with cancerous cells.
4. is usually not inherited.
5. is the result of genomic imprinting.

0.25 PointsA genetic counselor will know that the probability of having a child affected with a condition inherited as an autosomal recessive would be:

1. 0.5 or 50% if both parents were homozygous normal.
2. 0.5 or 50% if both parents were heterozygous.
3. 0.25 or 25% if both parents were homozygous normal.
4. 0.25 or 25% if both parents were heterozygous.
5. 0% if both parents were heterozygous.

0.25 PointsA karyotype reveals that an individual is XYY. Based on your knowledge of human genetics, you correctly conclude that this individual has ____, and is a phenotypically _____.

1. Turner syndrome; sterile female
2. Turner syndrome; fertile female
3. Klinefelter syndrome; sterile male
4. Klinefelter syndrome; fertile male
5. XXY karyotype; fertile male

0.25 PointsAccording to data from the ENCODE project, approximately 80% of the human genome is associated with biological function.

1. True
2. False

0.25 PointsAn advantage of chorionic villus sampling (compared with amniocentesis) is that:

1. chorionic villus sampling detects a much wider range of genetic defects than does amniocentesis.
2. chorionic villus sampling is much less expensive than is amniocentesis.
3. chorionic villus sampling is much less invasive than amniocentesis.
4. chorionic villus sampling is much easier to perform than amniocentesis.
5. chorionic villus sampling can be performed much earlier than amniocentesis.

0.25 PointsAn individual who inherits the specific chromosome ____ deletion from his/her ____ will most likely have Prader-Willi syndrome rather than Angelman syndrome.

1. 15; mother
2. 15; father
3. 21; mother
4. 21; father
5. 12; father

0.25 PointsAneuploidies describe:

1. a phenomenon that only occurs in plants.
2. a condition in which an extra chromosome is present or one is absent.
3. a defect that is always fatal in humans.
4. an uncommon condition in humans.
5. mutations that almost always have a beneficial effect on an individual.

0.25 PointsAutosomal aneuploidies arise by:

1. chromosome breakage and rejoining.
2. meiotic nondisjunction.
3. errors in crossing-over.
4. mistakes in chromosome replication.
5. mitotic nondisjunction.

0.25 PointsAutosomal monosomy is not seen in live births because:

1. its effects are so small as to be overlooked.
2. its effects do not set in until adulthood.
3. its effects are so lethal as to cause spontaneous abortion early in pregnancy.
4. it only occurs in sex chromosomes and therefore does affect nonreproductive function.
5. the births lead to the establishment of a clone of abnormal cells

0.25 PointsColchicine is a drug that:

1. arrests cells in mitotic telophase.
2. stimulates meiosis.
3. prevents DNA replication.
4. arrests cells in mitotic metaphase.
5. prevents cells from entering prophase.

0.25 PointsComparing the human and mouse genomes has revealed that the mouse and human:

1. share few genes.
2. genomes are identical.
3. genomes have no genes in common.
4. share most genes.
5. genomes have identical noncoding DNA.

0.25 PointsCri du chat syndrome arises from:

1. trisomy for chromosome 5.
2. deletion of part of chromosome 5.
3. a 14/21 reciprocal translocation.
4. nondisjunction.
5. a duplication of part of chromosome 15.

0.25 PointsDescribe how amniocentesis is used in the prenatal diagnosis of human genetic abnormalities. Then compare and contrast the benefits and risks associated with amniocentesis and chorionic villus sampling.

0.25 PointsDiscuss the necessity and benefits of the Genetic Information Nondiscrimination Act (GINA) of 2008.

0.25 PointsDown syndrome is an example of a ____ condition.

1. monosomic
2. disomic
3. trisomic
4. polyploid
5. transgenic

0.25 PointsDown syndrome is characterized by:

1. single base mutations.
2. the presence of 47 chromosomes per somatic cell.
3. increasing risk with younger maternal age.
4. the presence of an extra chromosome 18 in each somatic cell
5. the same symptoms observed in each individual.

0.25 PointsFragile X syndrome:

1. results in learning, attention, and hyperactivity disabilities in males.
2. is not inherited from the parents.
3. is characterized by a fragile site at the tip of the Y chromosome.
4. results from a deletion of CGG sequences in the fragile X gene.
5. is due to genomic imprinting..

0.25 PointsGene targeting has been used in mice to produce strains that were either homozygous or heterozygous for ____.

1. PKU
2. cystic fibrosis
3. Huntington’s disease
4. sickle cell anemia
5. Tays Sachs Disease

0.25 PointsGene therapy involves:

1. replacing all mutant alleles in body cells.
2. replacing poor copies of alleles with normal alleles.
3. replacing a mutant allele in certain body cells with a normal allele.
4. repairing mutant alleles in certain body cells.
5. improving gene expression in key body cells.

0.25 PointsGenetic screening can be used to identify:

1. only diseases caused by more than one gene.
2. diseases caused by single gene mutations.
3. non-genetic conditions..
4. chromosomal abnormalities.
5. predicted date of birth.

0.25 PointsGeneticists study pedigrees in order to predict how traits determined by phenotype are inherited from one generation to the next. _________________

1. True
2. False

0.25 PointsGenome-wide association scans compare the proteins of individuals with a particular disease to individuals without the disease. _________________

1. True
2. False

0.25 PointsHemophilia A is an example of a(n) _____ disease and is characterized by a lack of blood-clotting factor ____.

1. X-linked; VIII
2. sex-linked recessive; V
3. autosomal dominant; VIII
4. sex-linked dominant; V
5. autosomal recessive; VIII

0.25 PointsHuman genetics can be most effectively studied using:

1. offspring raised under controlled conditions.
2. experimental matings between true-breeding strains.
3. controlled matings.
4. population studies of large extended families.
5. population studies of small extended families.