Genetics - Ch 8

  1. What is the difference between genetics vs genomics?
    Genetics - study of single genes and their effects

    Genomics - study of functions and interactions in the genome
  2. What ethnic groups do thse disorders appear more often in?

    Tay Sachs
    Phenylketonuria (PKU)
    Cystic Fibrosis
    Sickle Cell Anemia
    Lactase deficiency
    Tay Sachs - Ashkenazi Jews

    Thalassemias - Mediterranean

    Phenylketonuria (PKU) - Norwegians

    Cystic Fibrosis - Ashkenazi Jews

    Sickle Cell Anemia - African Americans

    Lactase deficiency - Chinese
  3. The most important nursing function in genetics?
    Providing emotional support to the family during all aspects of counseling
  4. What is the difference between occurrence vs recurrence risk?
    Occurrence - no children yet but are know to be at risk for having them with a genetic disease

    Recurrence - producing one or more children with a genetic disease
  5. What two key findings were discovered in the human genome project?
    1) All humans are 99.9% identical at the DNA level

    2) 20,000-25,000 genes make up the human genome
  6. What is the difference between a carrier screening test vs predictive test?
    Carrier - identifies those who are carriers of a mutation but do not show symptoms

    Predictive - clarify genetic status of asymptomatic family members
  7. What is the difference between presymptomatic testing vs predispositional testing?
    Presym - if a gene mutation is present, symptoms should appear EX: Huntington's Disease

    Predis - if a gene mutation is present, it does NOT mean a 100% risk of developing the condition EX: Breast Cancer
  8. What is pharmacogenomics?
    The use of genetic information to individualize drug therapy
  9. What is the primary benefit in pharmacogenomics?
    To reduce adverse drug reactions
  10. Homologous chromosomes have the same number and arrangement except for?
    Male sex chromosomes (XY)
  11. What is an allele?
    Genes that code for different variations of the same trait
  12. What is a karyotype?
    The number, form and size of an individual's chromosomes
  13. What is the most commonly identified chromosome abnormality in humans?

    It is the leading known cause of what problems?

    Pregnancy and Mental Retardation
  14. What is mosaicism?
    Mixture of cells, some with a normal number of chromosomes and others missing or having an extra chromosome
  15. What is translocation of a chromosome?

    What can cause it?
    Exchanging chromosome material between two chromosomes

    Exposure to drugs, viruses and radiation
  16. What two chromosomes are commonly deleted?
    Short arm of 5

    Long arm of 18
  17. What are the most common sex chromosome abnormalities for each gender?
    Female - Turner's Syndrome (X)

    Male - Klinefelter's Syndrome (XXY)
  18. What are symptoms of Turner's syndrome?
    • Juvenile genitalia and underdeveloped ovaries
    • Short stature
    • Webbing of neck
    • Lymphedema in hands and feet
  19. What are the symptoms of Klinefelter's syndrome?
    • Poorly developed secondary sexual characteristics
    • Small testes
    • Infertile
    • Tall
    • Effeminate
  20. What is the difference between unifactorial vs multifactorial inheritance?
    Uni - A single gene controls a certain trait, disorder or defect

    Multi - Two or more genes on different chromosomes act together to control a certain trait, disorder or defect
  21. The most common congenital malformations result from ___________ inheritance.

    (Influenced by genes AND environment)
  22. What are four examples of a multifactorial inheritance?
    Cleft lip and palate

    Congenital heart disease

    Neural tube defects

    Pyloric stenosis
  23. What are the four types of unifactorial inheritance?
    • Autosomal dominant
    • Autosomal recessive
    • X-linked dominant
    • X-linked recessive
  24. Autosomal Dominant Inheritance

    Skipping of generations?
    Genders affected equally?
    Expressed with same symptoms?
    No, parent must have disorder as well


    No, can vary

    Huntington's Disease, Marfan Syndrome, Achondroplasia
  25. Autosomal Recessive Inheritance

    Skipping of generations?
    Genders affected equally?
    Yes, 25% chance of obtaining and can be carriers


    PKU, Sickle Cell, Tay Sachs, CF
  26. X-Linked Dominant Inheritance

    Genders affected equally?
    • No, males and heterozygous females
    • (females tend to be carriers)
    • (heterozygous females have 50% chance of transmitting to offspring)

    Rickets, Fragile X syndrome
  27. X-Linked Recessive Inheritance

    Skipping of generations?
    Genders affected equally?
    Expressed with same symptoms?
    • No, males
    • (females are carriers)

    Hemophilia, Color blindness, Duchenne muscular dystrophy
  28. True or False

    All congenital disorders are inherited.

    Some are exposed to teratogens at birth that will influence their genes
  29. Inadequate folic acid can cause?
    Neural tube defects
  30. Malnutrition during pregnancy can cause?
    • Low birth weight newborns
    • (which makes them more susceptible to infection or learning disabilities)
  31. True or False

    The embryo is susceptible to teratogens in the first two weeks of development?
  32. Where does fertilization take place?

    (outer third of the uterine tube)
  33. What is the zona reaction?
    When sperm enters into the ovum and a membrane then surrounds to make other sperm impenetrable
  34. What is the difference between a morula vs blastocyst?
    Morula - ball of cells produced within 3 days traveling to the uterus with its protective zona

    Blastocyst - cavity forms around the morula within 4 days that develops into an embryo
  35. What is chorionic villi vs decidua basalis?
    CV - projections that obtain oxygen from the mom to the embryo and dispose waste

    DB - where maternal blood vessels are for the chorionic villi to feed off of
  36. The length of pregnancy is predicted by ___________
    The first day of the last menstrual period
  37. What are the 3 primary germ layers?
    • Ectoderm
    • Mesoderm
    • Endocerm
  38. Ectoderm develops into...
    • Epidermis
    • Glands
    • Nails
    • Hair
    • CNS/PNS
    • Eye lens
    • Tooth enamel
  39. Mesoderm develops into...
    • Bones
    • Teeth
    • Muscles
    • Dermis
    • Connective tissue
    • Cardiovascular system
    • Spleen
    • Urogenital system
  40. Endoderm develops into...
    Lining of respiratory and digestive tracts
  41. What is the time frame for the embryo?
    15 days to 8 weeks after conception
  42. What is viability?
    The capability of the fetus to survive outside the uterus
  43. What is the most critical alveolar sufactant require for postnatal lung expansion?
  44. What does the L/S ratio determine?
    Fetal lung maturity

    (2:1 ratio = maturity)
  45. When do these systems begin development?

    3 weeks
  46. When do these systems begin development?

    4 weeks
  47. When do these systems begin development?

    5 weeks
  48. When do these systems begin development?

    7 weeks
  49. Dizygotic Twins

    Fraternal or Identical?
    Same sex?
    Fraternal (look different)

    Don't have to be
  50. Monozygotic Twins

    Fraternal or Identical?
    Same sex?

  51. How many hours of ovulation does fertilization occur?
    24 hours
  52. What is the only immunoglobulin that passes the placenta?

    What is its role?

    Passive acquired immunity to specific bacterial toxins
  53. By the end of the first trimester the fetus produces what immunoglobulin?

    Why is this produced?

    In response to blood group antigens, organisms and some viruses
  54. How does the baby obtain IgA?

    What kind of immunity does it provide?
    By the mothers breastmilk

    Passive immunity
Card Set
Genetics - Ch 8
Ch. 8