Test 2 Lecture 1

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Test 2 Lecture 1
2013-09-22 17:47:42
Test Lecture

Test 2 Lecture 1
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  1. What is a gene?
    A specific segment of DNA that contains the genetic code for a specific protein.
  2. What does it mean when a gene is expressed?
    A gene is only expressed when the protein it codes for is produced.
  3. What is a mutated gene?
    A gene that has been altered therefore it codes for an altered or abnormal protein.
  4. When does replication of DNA occur?
    Prior to cell division during INTERPHASE of mitosis.
  5. What is each new double stranded helix made up of?
    1 new strand and 1 old strand (parent strand)
  6. Somatic (body) cell division is also called what?
  7. Sex cell division is also called what?
  8. Human somatic cells contain how many chromosomes?
    • 2 sets, 1 maternal, 1 paternal making
    • 23 pairs of chromosomes or
    • 46 chromosomes = diploid
  9. Human sex cells contain how many chromosomes?
    1 set of 23 chromosomes which makes 23 total = haploid
  10. During somatic cell cycle what phase does replication of DNA and cenrosomes occur?
    S phase
  11. Meiosis consists of how man cell divisions and how many DNA replications?
    • 2 cell divisions
    • 1 replication of DNA
  12. During Prophase 1, what is a factor responsible for genetic variation?
    Crossing over
  13. During Metaphase 1 what is another factor in genetic variation?
    Independent Assortment
  14. Mitosis occurs in what kind of cells?
    somatic cells
  15. What is the name of the process of dividing the replicated DNA that results in 2 identical "daughter" cells each with 46 Chromosomes?
  16. Meiosis occurs in what kind of cells?
    sex cells
  17. What is the name of the process that divides replicated DNA after crossing over / independent assortment (genetic variation) have occurred and involves a 2nd division that results in NON-identical cells each with 23 Chromosomes.
  18. What is the name the chromosomal chart?
  19. What is the name of the process that occurs when both members of a homologous pair of chromosomes go into the same daughter cell in meiosis I, OR when sister chromatids fail to separate in Meiosis II?
  20. What are the results of nondisjunction?
    Monosomy- cell has only 1 copy of a chromosome (Turner syndrome (only one X chromosome)

    Trisomy- cell has 3 copies of a chromosome (Down's syndrome) multiple copies
  21. What are some characteristics of cancer cells?
    • Lack differentiation- do not contribute to body functions
    • Unlimited ability to divide- uncrontrolled growth
    • Undergo angiogenesis-formation of new blood vessels to supply nutrients/O2
    • Become abnormal gradually-through a multistage process-takes time
    • Form malignant tumors-eventually invades surrounding tissue
    • Have abnormal morphology- nuclei that are enlarged and may have an abnormal number of chromosomes; cells not uniform