Biology 2nd semester

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Biology 2nd semester
2010-05-29 17:38:34

Study for 2nd semester exams
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  1. What is a gene map?
    an arrangement of genes on a chromosome
  2. What is a tetrad?
    A four-part structure that forms during the prophase of meiosis and consists of two homologous chromosomes, each composed of two sister chromatids
  3. What is crossing-over?
    Process in which homologous chromosomes exchange portions of their chromatids during meiosis
  4. What is homologous?
    Refers to chromosomes that have a corresponding chromosome from the opposite sex parent.
  5. What is diploid?
    cell that contains both sets of homologous chromosomes
  6. What is haploid?
    cell that only contains a single set of chromosomes (genes)
  7. What is cyclin?
    protein that regulates the cell cycle in eukaryotic cells
  8. What is cancer?
    disorder in which some of the body's own cells lose the ability to control growth.
  9. What are centrioles?
    one of two tiny structures located in the cytoplasm of animal cells near the neuclear envelope
  10. What are spindles?
    fanlike microtubule structure that helps seperate the chromosomes during mitosis
  11. What are chromatids?
    one of two identical "sister" parts of a duplicated chromosome.
  12. What are centromeres?
    area where the chromosomes of a chromosome are attached
  13. What is cell division?
    process where a cell divides into two daughter cells
  14. What is mitosis?
    part of eukaryotic cell division where the cell neucleus divides
  15. What is meiosis?
    process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell
  16. What is heredity?
  17. What is genetics?
    the scientific study of heredity
  18. What is hybrid?
    offspring of crosses between parents with different traits.
  19. What is dominant?
    • AA - the big A is dominant
    • Aa - the big A is dominant over little a
  20. what is recessive?
    aa - little a is the recessive.
  21. what is heterozygous?
    an organism that has two different alleles for the same trait
  22. what is homozygous?
    an oragnism that has two of the same allele for a trait
  23. what is co-dominance?
    both alleles in a genotype occur in the phenotype
  24. what is incomplete dominance?
    one allele is not completely dominant over the other
  25. what are polygenic tratis?
    trait controlled by two or more genes
  26. what is a allele?
    one of a number of different forms for a gene
  27. what is a genotype?
    genetic makeup of a organism
  28. what is a phenotype?
    physical characteristics of a organism
  29. what is a autosome?
    chromosome that isn't a sex chromosome
  30. what is a sex chromosome?
    one of two chromosomes that determines a individuals gender
  31. what is a pedigree?
    chart that shows relationships through a family
  32. what is selective breeding?
    only the individuals with the desired traits to produce for the next generation
  33. what is hybridization?
    crossing dissimilar organisms to bring together the best traits of both organisms
  34. what is inbreeding?
    breeding of individuals with similar desired traits to maintain those traits
  35. what is a mutagen?
    any agent (physical or environmental) that can induce a genetic mutation or can increase the rate of mutation
  36. what is recombinant DNA?
    dna produced by combining dna from different sources
  37. what is a restriction enzyme?
    enzyme that cuts DNA at a specific sequence of nucleotides.
  38. what is a gene pool?
    combined genetic information of all members of a particular species
  39. what is genetic drift?
    random changes of allele frequencies that occur in small populations
  40. what is fitness?
    the ability to survive in your environment (survival of the fittest)
  41. what is adaptation?
    inherited characteristic that increases an organisms chance of survival
  42. what is natural selection?
    • "survival of the fittest"
    • individuals that are better suited to their environment survive and reproduce more successfully
  43. what is relative frequency?
    # of times an allele occurs in the gene pool compared with the # of times the other alleles occur
  44. what is evolution?
    change in a kind of organisms over time

    ALSO: the process where modern organisms have descended from ancient organisms.
  45. what is variation?
    different types
  46. what is genetic equilibrium?
    situation where allele frequencies remain constant.
  47. what is convergent evolution?
    unrelated organisms evolve similarities while living in similar enviroments
  48. what is gradualism?
  49. what is punctuated equilibrium?
    long stable periods interrupted by brief periods of rapid changes
  50. what is co-evolution?
    adapting and evolving in response to another organism.
  51. what is embryology?
  52. what is adaptive radiation?
    single species evolves into several different forms that live in different ways
  53. label the different parts of a chromosome: