NSG 5003 Week 3 quiz | Complete Questions & Answers Fall 2025.

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Chapter 4: Genes and Genetic Diseases MULTIPLE CHOICE 1. Inserting bone marrow cells into an individual who produces abnormal erythrocytes is an example of what type of therapy? a. Somatic cel... l c. Genetic engineering b. Germ cell d. Recombinant DNA A Gene therapy can be applied in two ways. The less controversial approach is somatic cell therapy, which consists of inserting normal genes into the cells of an individual who has a genetic disease. In this approach, a particular tissue, such as bone marrow cells that produce abnormal erythrocytes, is treated. The correct option is the only one that accurately identifies the therapy described in the question. PTS: 1 REF: Page 137 | Box 4-2 2. DNA replication requires the enzyme DNA polymerase to: a. Travel along the single DNA strand, adding the correct nucleotide to the new strand b. Move along the double strand of DNA to unwind the nucleotides of the double helix c. Hold the double strand apart while the correct nucleotides are added to the strand d. Transport the double strand of DNA from the nucleus to the cytoplasm for protein formation A The DNA polymerase enzyme travels along the single DNA strand, adding the correct nucleotides to the free end of the new strand (see Figure 4-2, B). The correct option is the only one that accurately describes the process involved in DNA replication using DNA polymerase. PTS: 1 REF: Page 137 3. Transcription is best defined as a process by which: a. DNA polymerase binds to the promoter site on ribonucleic acid (RNA). b. RNA directs the synthesis of polypeptides for protein synthesis. c. RNA is synthesized from a DNA template. d. A base pair substitution results in a mutation of the amino acid sequence. C Transcription is the process by which RNA is synthesized from a DNA template. The correct option is the only one that accurately defines the term transcription. PTS: 1 REF: Page 141 4. The purpose of a staining technique of chromosomes such as Giemsa is to: a. Permit the mitotic process to be followed and monitored for variations. b. Allow for the numbering of chromosomes and the identification of variations. c. Identify new somatic cells formed through mitosis and cytokinesis. d. Distinguish the sex chromosomes from the homologous chromosomes. B One of the most commonly used stains is Giemsa stain. By using banding techniques, chromosomes can be unambiguously numbered, and individual variation in chromosome composition can be studied. Missing or duplicated portions of chromosomes, which often result in serious diseases, also can be readily identified. The correct option is the only one that accurately describes the purpose of the Giemsa staining technique. PTS: 1 REF: Pages 142-143 5. An amniocentesis indicates a neural tube defect when an increase in which protein is evident? a. Chorionic c. Amniotic b. Alpha fetoprotein d. Embryonic B Other disorders can be detected with this procedure. These include most neural tube defects, which cause an elevation of alpha fetoprotein in the amniotic fluid, and hundreds of diseases caused by mutations of single genes. The correct option is the only one that accurately identifies the protein responsible for a neural tube defect. PTS: 1 REF: Page 136 | Box 4-1 6. An amniocentesis is recommended for pregnant women who: a. Have a history of chronic illness b. Have a family history of genetic disorders c. Have experienced in vitro fertilization d. Had a late menarche B Amniocentesis is recommended only for pregnancies known to have an elevated risk for a genetic disease or in women older than 30 to 35 years of age. The correct option is the only one that accurately describes a criterion for ordering an amniocentesis. PTS: 1 REF: Page 136 | Box 4-1 7. The most clinically useful technique for prenatal diagnosis of chromosomal abnormalities at 3 months’ (12 weeks’) gestation is: a. Gene mapping c. Amniocentesis b. Linkage analysis d. Chorionic villus sampling D Chorionic villus sampling consists of extracting a small amount of villous tissue directly from the chorion. This procedure can be performed at 10 weeks’ gestation and does not require in vitro culturing of cells; sufficient numbers are directly available in the extracted tissue. Thus the procedure allows prenatal diagnosis at approximately 3 months’ gestation rather than at nearly 5 months’ gestation. The correct option is the only one that accurately describes the most useful technique for prenatal diagnosis of chromosomal abnormalities. PTS: 1 REF: Page 136 | Box 4-1 8. The term for an error in which homologous chromosomes fail to separate during meiosis or mitosis is: a. Aneuploidy c. Polyploidy b. Nondisjunction d. Translocation B Aneuploidy is usually the result of nondisjunction, an error in which homologous chromosomes or sister chromatids fail to separate normally during meiosis or mitosis. The correct option is the only one that is used to describe an error in chromosomal separation during reproduction. PTS: 1 REF: Page 145 9. Which clinical manifestations would be expected for a child who has complete trisomy of the twenty-first chromosome? a. Widely spaced nipples, reduced carrying angle at the elbow, and sparse body hair b. An IQ of 25 to 70, low nasal bridge, protruding tongue, and flat, low-set ears c. High-pitched voice, tall stature, gynecomastia, and an IQ of 60 to 90 d. Circumoral cyanosis, edema of the feet, short stature, and mental slowness B Individuals with this disease are mentally retarded, with IQs usually ranging from 25 to 70. The facial appearance is distinctive and exhibits a low nasal bridge, epicanthal folds (which produce a superficially Asian appearance), protruding tongue, and flat, low-set ears. The correct option is the only one that accurately describes the clinical manifestations of the complete trisomy of the twenty-first chromosome. PTS: 1 REF: Pages 146-147 10. What is the most common cause of Down syndrome? a. Paternal nondisjunction c. Maternal nondisjunction b. Maternal translocations d. Paternal translocation C Nondisjunction during the formation of one of the parent’s gametes or during early embryonic development occurs in approximately 97% of infants born with Down syndrome. In approximately 90% to 95% of infants, the nondisjunction occurs in the formation of the mother’s egg cell. The correct option is the only one that accurately describes the most common cause of Down syndrome. PTS: 1 REF: Page 147 11. What syndrome, characterized by an absent homologous X chromosome with only a single X chromosome, exhibits features that include a short stature, widely spaced nipples, and webbed neck? a. Down c. Turner b. Cri du chat d. Klinefelter C In Turner syndrome, a sex chromosome is missing, and the person’s total chromosome count is 45. Characteristic signs include short stature, female genitalia, webbed neck, shieldlike chest with underdeveloped breasts and widely spaced nipples, and imperfectly developed ovaries. The correct option is the only one that accurately describes the clinical manifestations described in the question. PTS: 1 REF: Page 147 12. A person with 47, XXY karyotype has the genetic disorder resulting in which syndrome? a. Turner c. Down b. Klinefelter d. Fragile X B A disorder in the chromosome (47, XXY karyotype) results in a disorder known as Klinefelter syndrome. The correct option is the only one that accurately describes a genetic disorder that exhibits the described genetic configuration. PTS: 1 REF: Page 148 13. What is the chromosomal variation that causes Klinefelter syndrome? a. Nondisjunction of the X chromosome in the father b. Translocation of the X chromosome in the mother c. Nondisjunction of X chromosome in the mother d. Translocation of the Y chromosome in the father C Nondisjunction of the X chromosomes in the mother causes Klinefelter syndrome in the majority of infants, and the frequency of the disorder rises with maternal age. The correct option is the only one that accurately describes the chromosomal variation characteristic of Klinefelter syndrome. PTS: 1 REF: Page 148 14. What is the second most commonly recognized genetic cause of mental retardation? a. Down syndrome c. Klinefelter syndrome b. Fragile X syndrome d. Turner syndrome B The fragile X syndrome is the second most common genetic cause of mental retardation (after Down syndrome). The correct option is not observed with enough frequency to be recognized as the second most common cause of mental retardation. PTS: 1 REF: Page 151 15. What is the blood type of a person who is heterozygous, having A and B alleles as codominant? a. A c. O b. B d. AB D When the heterozygote is distinguishable from both homozygotes, the locus is said to exhibit codominance. An example is the ABO blood group, in which heterozygotes having the A and B alleles express both of them as A and B antigens on their red cells (forming blood group AB). The correct option is the only one that accurately describes codominance. PTS: 1 REF: Page 151 16. A couple has two children diagnosed with an autosomal dominant genetic disease. What is the probability that the next child will have the same genetic disease? a. One sixth c. One third b. One fourth d. One half D Affected heterozygous individuals transmit the trait to approximately one half of their children; however, because gamete transmission is subject to chance fluctuations, it is possible that all or none of the children of an affected parent may have the trait. Nevertheless, when large numbers of matings of this type are studied, the proportion of affected children closely approach one half. PTS: 1 REF: Pages 152-153 17. When a child inherits a disease that is autosomal recessive, it is inherited from: a. Father [Show More]

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