1. What is a karyotype?
    a picture of chromosomes aranged in pairs from largest to smallest
  2. How many chromosomes do humans have?
    46 individual, or 23 pairs; 23 from egg and 23 from sperm
  3. How many pairs of autosomes do humans have?
  4. How many pairs of sex chromosomes do humans have?
  5. What is a pedigree?
    chart showing the relationship of traits within a family; square-male circle-female
  6. What is the human genome and how many genes does it have?
    human complete set of genetic information, 20,000-25,000
  7. What was the rhesus blood group named after?
    rhesus monkey
  8. What is an example of recessive disease?
    PKU phenylketunuria, albinism
  9. What is an example of a dominant disease?
    huntingtons, dwarfism
  10. What is an example of a codominant disease?
    sickle cell anemia
  11. What is sickle cell?
    when you produce sickle shaped blood cells and they get stuck in the blood vessles and cause lots of apain and block the flow of blood damaging tissues/organs
  12. What is chromosome inactivation?
    when one x is randomly switched off and forms a Barr Body (the chromosome forms a dense region in the nucleus)
  13. What is responsible for different color spots in femae cats?
    chromosome inactivation
  14. What is nondisjunction?
    when homologous chromosomes fail to separate
  15. The most common error in meiosis occurs when___.
  16. When might an individual be born with three copies of a chromosome?
    if two copies of an autosomal chromosome fails to separate during meiosis
  17. What is monosomy?
    missing  a chromosome in a pair
  18. what is ploidy?
    entire sets of chromosome
  19. How many base pairs are there in your DNA?
    roughly 6 billion
  20. When was the human genome complete?
    June 2000
  21. What is gene therapy?
    an absent or faulty gene replaced by a normal working  gene
  22. What are the steps of gene therapy?
    • an absent or faulty gene replaced by a normal working  gene
    • the body can then make the correct protein or enzyme, eliminating the cause of the disorder
    • viruses are then used because of their ability to enter a cells DNA
    • virus particles are modified so they cannot cause disease
    • a DNA fragment containing a replacement gene is spliced to viral DNA
    • the patient is then infected with the modified virus particles which should carry the gene into cells to correct genetic defects
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