Textbook Question
In what way does position effect variegation (PEV) of Drosophila eye color indicate that chromatin state can affect gene transcription?
Ch. 10 - Eukaryotic Chromosome Abnormalities and Molecular Organization
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172
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Table of contents
- Ch. 1 - The Molecular Basis of Heredity, Variation, and Evolution64
- Ch. 2 - Transmission Genetics144
- Ch. 3 - Cell Division and Chromosome Heredity81
- Ch. 4 - Gene Interaction87
- Ch. 5 - Genetic Linkage and Mapping in Eukaryotes103
- Ch. 6 - Genetic Analysis and Mapping in Bacteria and Bacteriophages73
- Ch. 7 - DNA Structure and Replication71
- Ch. 8 - Molecular Biology of Transcription and RNA Processing79
- Ch. 9 - The Molecular Biology of Translation110
- Ch. 10 - Eukaryotic Chromosome Abnormalities and Molecular Organization100
- Ch. 11 - Gene Mutation, DNA Repair, and Homologous Recombination86
- Ch. 12 - Regulation of Gene Expression in Bacteria and Bacteriophage90
- Ch. 13 - Regulation of Gene Expression in Eukaryotes38
- Ch. 14 - Analysis of Gene Function via Forward Genetics and Reverse Genetics72
- Ch. 15 - Recombinant DNA Technology and Its Applications69
- Ch. 16 - Genomics: Genetics from a Whole-Genome Perspective49
- Ch. 17 - Organelle Inheritance and the Evolution of Organelle Genomes27
- Ch. 18 - Developmental Genetics43
- Ch. 19 - Genetic Analysis of Quantitative Traits66
- Ch. 20 - Population Genetics and Evolution at the Population, Species, and Molecular Levels105
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172Not the one you use?Change textbook
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Sanders 3rd EditionCh. 10 - Eukaryotic Chromosome Abnormalities and Molecular OrganizationProblem B.11a
Sanders 3rd EditionCh. 10 - Eukaryotic Chromosome Abnormalities and Molecular OrganizationProblem B.11aChapter 10, Problem B.11a
The most common reason a physician might recommend that a woman have maternal serum screening and a karyotype analysis is concern that her fetus may have Down syndrome. Go to the OMIM website at www.ncbi.nlm.nih.gov/omim and look up Down syndrome (OMIM 190685).
List the main symptoms of Down syndrome.
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Understand that Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21, also known as trisomy 21.
Go to the OMIM website at www.ncbi.nlm.nih.gov/omim and enter the OMIM number 190685 or search for 'Down syndrome' to access detailed genetic and clinical information.
Locate the section on the OMIM page that describes the clinical features or main symptoms associated with Down syndrome.
Identify and list the common symptoms, which typically include intellectual disability, characteristic facial features, hypotonia (low muscle tone), and congenital heart defects, among others.
Summarize the main symptoms clearly, ensuring you capture both physical and developmental characteristics as described in the OMIM entry.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Down Syndrome and Its Genetic Basis
Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21 (trisomy 21). This chromosomal abnormality leads to developmental and physical changes, including intellectual disability and characteristic facial features. Understanding its genetic cause is essential for interpreting karyotype results.
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Genetics Basics
Maternal Serum Screening
Maternal serum screening is a prenatal test that measures specific proteins and hormones in a pregnant woman's blood to assess the risk of chromosomal abnormalities like Down syndrome. It is a non-invasive method used to identify pregnancies that may require further diagnostic testing.
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Karyotype Analysis
Karyotype analysis is a laboratory technique that visualizes an individual's chromosomes under a microscope to detect numerical or structural abnormalities. In prenatal diagnosis, it confirms the presence of trisomy 21 by identifying the extra chromosome responsible for Down syndrome.
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Related Practice
Textbook Question
The most common reason a physician might recommend that a woman have maternal serum screening and a karyotype analysis is concern that her fetus may have Down syndrome. Go to the OMIM website at www.ncbi.nlm.nih.gov/omim and look up Down syndrome (OMIM 190685).
Summarize what is known about the location and genes found within the DSCR.
Textbook Question
The most common reason a physician might recommend that a woman have maternal serum screening and a karyotype analysis is concern that her fetus may have Down syndrome. Go to the OMIM website at www.ncbi.nlm.nih.gov/omim and look up Down syndrome (OMIM 190685).
How might those genes lead to the main symptoms of Down syndrome?
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Textbook Question
The most common reason a physician might recommend that a woman have maternal serum screening and a karyotype analysis is concern that her fetus may have Down syndrome. Go to the OMIM website at www.ncbi.nlm.nih.gov/omim and look up Down syndrome (OMIM 190685).
Look at the 'Mapping' and 'Molecular Genetics' sections and describe what is meant by the Down syndrome critical region (DSCR).
Textbook Question
A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes):
Chromosome 1RNMDHBGKWU
Chromosome 2RNMDHBDHBGKWU
What term best describes this situation?
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Textbook Question
A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes):
Chromosome 1RNMDHBGKWU
Chromosome 2RNMDHBDHBGKWU
Diagram the pairing of these homologous chromosomes in prophase I.