Bio: Genetics

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Bio: Genetics
2011-01-23 12:18:57

bio tingz
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  1. Whats a nucleotide???
    part of a strand of DNA- phosphate, sugar, and nitrogen base
  2. what would be the complimentary DNA strand to ATGGCTTA?
  3. what is DNA?
    deoxyribonucleic acid... genetic information; coding for everything our cells do- strands of phosphates, sugars, and nitrogen bases
  4. Whats chromatin?
    present in interphase; spaghetti; DNA strands
  5. what are chromatids?
    wound chromatin; two chromatids attached with a centromere make a chromosome; seperated in anaphase
  6. what are chromosomes?
    two chromatids attached with a centromere; we have 46 chromosomes
  7. difference between mitosis and meiosis?
    meiosis goes through mitosis twice; creates 4 daughter cells instead of 2; used to make gametes
  8. describe interphase!!!
    nucleus intact, chromatin, 46 chromosomes!
  9. describe prophase!!!
    DNA duplicates, nucleus dissolves, spindle fibres start to grow
  10. describe metaphase!!!
    spindle fibres align chromosomes at the equator of the cell
  11. describe anaphase!!
    spindle fibres pull chromosomes and pull chromatids to opposite poles of the cell
  12. describe telophase!!
    • cytokinesis tingzzz (:
    • cleavage furrowing, two daughter cells, nucleus reforms
  13. when does crossing over take place?
    whats crossing over?
    metaphase; synapsis- exchange of genetic information between chromosomes, allows genetic variation
  14. difference between haploid and diploid cells?
    • haploid: n (gametes; 23)
    • diploid: 2n (body cells; 46)
  15. what is oogenesis?
    meiosis; production of ovum/eggs; gametes/haploid; only one viable egg
  16. what is spermatogenesis?
    meiosis; production of sperm; gametes/haploid; all four sperm are viable
  17. define genotype!!
    genetic make-up of an individual
  18. define phenotype!!!
    visible alleles of an individual
  19. what is non-disjunction?
    when sister chromatids don't seperate in anaphase
  20. what is trisomy 18?
    non disjunction; causing a gamete to have one more chromosome 18; the zygote will have a third chromosome 18
  21. whats a monohybrid cross?
    crossing ONE allele; punnett squares nd tingzz
  22. whats a dihybrid cross?
    crossing TWO allels; punnett squares nd tingzz
  23. dominant vs. reccessive alleles
    • dominant: will show even if only one of the two genes represents that allele
    • recessive: needs both alleles to show; someone can be a carrier of a recessive gene
  24. homozygous vs. heterozygous
    • homozygous: a pair of genes representing the same allele
    • heterozygous: a pair of genes representing different genes
  25. what were Mendels laws?
    • 1: law of segregation
    • - only one version of an allele can be represented in a gamete
    • 2: law of independent assortment
    • - the inheritance of one trait doesn't affect the inheritance of another
  26. why did Mendel use pea plants in his experiment? (3 things)
    • - they grow quickly
    • - they can only show one trait or another
    • - they are very low maintenance
  27. codominance vs. incomplete dominance?
    • codominance: when the two versions of the allele are dominant and both alleles are present (i.e. red and white alleles would make a red and white striped individual)
    • incomplete dominance: when the two versions of the allele are recessive and a blend of the alleles is shown (i.e. red and white would make a pink individual
  28. whats a test cross?
    when the possibilities of an unknown genotype of an individual are crossed with a homozygous recessive individual to determine the unknown genotype
  29. why are males more affected with x-linked disorders?
    because they only have one x-chromosome so they only need one affected chromosome to become affected
  30. advantages and disadvantages of asexual reproduction?
    • advantages: faster, simpler, only requires one organism
    • disadvantages: lack of genetic variation
  31. purpose of mitosis?
    allows organisms to grow and repair
  32. whats cytokinesis?
    the division of cytoplasm
  33. gamete vs. somatic cell?
    • gamete: sex cell; haploid cell
    • somatic cell: body cell; diploid cell
  34. where does spermatogenesis/oogenesis occur?
  35. when does spermatogensis/oogenesis occur?
    puberty/embryo until birth
  36. length of mitotic production for spermatogenesis/oogenesis?
  37. what changes can occur in chromosome structure?
    • deletion: a portion of the chromosome is lost
    • duplication: a gene sequence is repeated
    • inversion: a gene segments order is reversed
    • translocation: a fragment of one chromosome attaches to another
  38. explain the cell cycle (the phases)
    • S phase: synthesis; dna is replicated
    • G1: gap between mitosis and S
    • G2: gap between S and mitosis; cell is ready to divide
  39. what is cancer?
    uncontrolled cell division
  40. how does someone get cancer?
    carcinogens mutate the oncogenes which control the cell's replication mechanisms
  41. what is angiogenesis? (cancer)
    the process of developing a system of arteries and veins to supply blood to the tumour
  42. what is metastasis? (cancer)
    when some of the cancer cells break loose and move through the blood stream to another part of the body where it starts to multiply
  43. what are the two basic treatments for cancer?
    surgery to remove the tumour (metasticized parts could be small) /radiation to kill the cancer cells (also kills other cells, some cells may be immune)
  44. eukaryotic vs. prokaryotic cells?
    eukaryotic has a nucleus/ prokaryotic doesn't
  45. whats a karyotype?
    an ordered display of an individual's chromosomes from mitotic cells; staining can reveal band patterns
  46. whats a homologous pair of chromosomes?
    pairs of chromosomes with the same banding pattern; one from the mother one from the father (minus x and y)
  47. autosomal crosses, test crosses, sex-linked crosses, blood type crosses,
    yeeeeeeeeeeeeeeeee!!! (: