bio 1 test 3

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bio 1 test 3
2012-04-16 13:37:55

bio 1 test 3 ch 12, 13, 14, 15
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  1. cell cycle
    from the time a cell is first formed from a dividing parent cell until it's own division into two daughter cells
  2. chromosomes are made of
    DNA and proteins
  3. chromatin
    the entire complex of DNA and proteins that is the building material of chromosomes
  4. humans are 2n=
  5. human gametes are n=
  6. all animals have ____________ number(s) of chromosomes
  7. sister chromatids
    joined, identical copies of the original chromosome
  8. centromere
    where the chromatid is attached most closely to it's sister chromatid (waist).
  9. Part of a chromatid on either side of the centromere
  10. mitosis
    nuclear division to make identical cells
  11. cytokinesis
    division of the cytoplasm
  12. sister chromatid cohesion
    how chromatids are connected before they split
  13. mitotic (M) phase
    mitosis and cytokinesis. The shortest part of the cell cycle
  14. Interphase
    90% of the cell cycle. Consists of G1 (grows, carries out normal business, 5-6 hours), S (replicates chromosomes, 10-12 hours) and G2 (grows and prepares, 4-6 hours)
  15. how often does mitosis occur?
    maybe once in 24 hours (M less than 1 hour)
  16. stages of mitosis
    prophase, prometaphase, metaphase, anaphase, telophase (with cytokinesis)
  17. mitotic spindle
    fibers made of microtubules and proteins from other microtubules in the cytoskeleton. Indcludes 2 centrosomes, spindle microtubules and the asters. Make cells line up
  18. centrosome
    microtubule-organizing center. Part of spindle. A pair of centrioles is part of it. Duplicates, moves to opposite poles. Surrounded by asters/microtubules
  19. aster
    array of short microtubules extending from each centrosome
  20. kinetochore
    part of a sister chromatid which is grabbed onto by the microtubules during mitosis
  21. S Interphase
    chromatids duplicate
  22. chromatids duplicate into sister chromatids
    S Interphase
  23. Prophase
    chromosomes condense, nucleoli disappear, mitotic spindle begins to form
  24. chromosomes condense, nucleoli disappear, mitotic spindle begins to form
  25. prometaphase
    nuclear envelope fragments, kinetochores form, attach to microtubules
  26. nuclear envelope fragments
  27. metaphase
    centrosomes are at opposite ends of the cell, chromosomes line up at the equator
  28. centrosomes are at opposite ends of the cell, chromosomes line up at the equator
  29. anaphase
    shortest stage of mitosis, cohesion proteins are cleaved, sister chromatids part and become chromosomes, move toward opposite ends of the cell, cell elongates
  30. shortest stage of mitosis, cohesion proteins are cleaved, sister chromatids part and become chromosomes, move toward opposite ends of the cell, cell elongates
  31. telophase
    two daughter nuclei form in the cell, nuclear envelopes begin to form, nucleoli reappear, chromosomes become less condensed, mitosis is complete
  32. two daughter nuclei form in the cell, nuclear envelopes begin to form, nucleoli reappear, chromosomes become less condensed, mitosis is complete
  33. clevage
    animal cytokinesis
  34. first sign of cytokinesis in animal cells
    cleavage furrow
  35. cytokinesis in plant cells
    cell plate formation
  36. binary fission
    "division in half". When a prokaryote reproduces by growing to double it's size and then dividing into two cells.
  37. cell checkpoint
    a "stop" or "go ahead" signal for mitosis
  38. G0 phase
    nondividing phase caused by lack of "go ahead" at the G1 checkpoint. Many adult cells never divide, like nerves and muscles. Liver can be called back from G0 phase if needed
  39. density-dependant inhibition
    crowded cells stop dividing. Cultured cells will divide until they form a single layer of cells, then stop.
  40. anchorage
    cells will not divide unless attached to a particular substance--a form of inhibition to stop overcrowding
  41. cancer
    uncontrolled mitosis that ignores regulatory signals. Cells seem to be immortal and need no growth factor. They do not obey normal controls that require suicide when a mistake is made
  42. transformation
    process that converts a normal cell into a cancer cell
  43. benign tumor
    cells have too few genetic and cellular changes to survive at another site, so stay where they are. Usually do not cause problems
  44. malignant tumor
    cells whose genetic and cellular changes allow them to spread to new tissues and impair functions of one or more organs. May have unusual numbers of chromosomes, metabolism may be disabled and may cease to function constructively. Call blood vessels towards themselves.
  45. metastasis
    spread of cancer cells to locations distant from their original site
  46. cancer treatment
    radiation that damages the DNA in cancer cells (they cannot repair it), drugs that are toxic to actively dividing cells, or freezes the mitotic spindle, stopping cells from going beyond metaphase.
  47. heredity, inheritance
    transmission of traits from one generation to the next
  48. variation
    differences inherited by meiosis
  49. genetics
    study of heredity and hereditary variation
  50. diploid cell
    2 chromosome sets (mom and dad). 2n
  51. haploid cell
    1 chromosome set. n (sex cells in humans)
  52. gametes
    reproductive cells in animals and plants
  53. fertilization
    when gametes (sperm and egg) unite nuclei to pass on genes of both parents to offspring
  54. DNA is in:
    chromosomes in the nucleus, except for a small amount in the mitochondria and the chloroplasts
  55. somatic cells
    all the cells of the body except the gametes
  56. locus
    a gene's location along the length of the chromosome
  57. asexual reproduction
    mitosis, giving rise to exact genetic copies or clones
  58. clone
    product of asexual reproduction
  59. life cycle
    generation-to-generation sequence of stages in the reproductive history of an organism (conception to reproduction)
  60. karyotype
    image of chromosomes arranged in pairs, from the longest to the shortest
  61. homologous chromosomes (homologs)
    pairs of chromosomes with same length, centromere position and staining pattern. Control same inherited characters (eye color, etc.)
  62. sex chromosomes
    X and Y--not homologous. Determine an individual's sex
  63. autosomes
    all chromosomes except the sex chromosomes
  64. non-sister chromatids
    one maternal and one paternal chromatid (any two chromatids that are not sister)
  65. zygote
    fertilized egg (diploid)
  66. cells of the human body not produced by mitosis
  67. meiosis
    a type of cell division that reduces the number of sets of chromosomes from two to one in the gametes (animals, plants, fungi, some algae, some protists)
  68. alternation of generations
    multicellular diploid (sporophyte becomes haploid spore) and haploid (gametophyte) stages of plants and some algae, where sporophyte produces a gametophyte and gametophytes produce sporophytes.
  69. product of meiosis
    4 haploid daughter cells
  70. allele
    different variations of genes
  71. prophase I
    chromosomes condense and homologs loosely pair along their lengths, become physically connected (synapsis), cross over, homologs split back apart, centrosomes move, spindle forms, and nuclear envelope breaks down, then microtubules at the poles attach to kinetochores.
  72. metaphase I
    pairs of homologus chromosomes arrange at metaphase plate (equator)
  73. Anaphase I
    homologus pairs separate (sister chromatids stay together)
  74. telophase I and cytokinesis
    each half of the cell has a complete haploid set of duplicated chromosomes (sister chromatids that have crossed over). Cytokinesis and telophase I occur simultaneously, forming 2 haploid daughter cells with duplicated chromosomes.
  75. prophase II
    spindle apparatus forms
  76. metaphase II
    chromosomes (not genetically identical) are positioned at metaphase plate. Kinetochores attach to microtubules.
  77. anaphase II
    non-identical sister chromatids separate
  78. telophase II and cytokinesis
    nuclei form, chromosomes decondense, cytokinesis occurs. 4 non-identical haploid daughter cells are formed from the 2 haploid daughter cells of Meiosis I.
  79. chiasmata
    x-shaped regions of homologous pairs of chromosomes where crossovers occur
  80. crossing over
    genetic rearrangement between non-sister chromatids by exchanging corresponding segments of DNA, at a chiasma and during synapsis
  81. synapsis
    a state in which paired homologous chromosomes are physically connected along their lengths by a zipper-protein
  82. role of mitosis
    enables multicellular adult to arise from zygote, produces cells for growth, repair and asexual reproduction
  83. role of meiosis
    produces gametes: reduces number of chromosome sets by half and introduces genetic variability.
  84. number of possible combinations in gametes
    2n (humans is 223 = 8.4 million). Adding crossing over makes it infinite
  85. recombinant chromosomes
    chromosomes that have participated in crossing over
  86. monk who studied pea plants and discovered modern genetics
    Gregor Mendel
  87. character
    a heritable feature that varies among individuals (flower color)
  88. trait
    each variant for a character (purple or white colors for flowers)
  89. meiosis in plants produces
  90. pea plant sex organs
    stamen and carpel
  91. pea plants reproduce by
  92. true-breeding
    varieties that, over many generations, produced only the same variety as the parent plant
  93. hybridization
    mating or crossing of two true-breeding varieties
  94. P generation
    true-breeding parents
  95. F1 generation
    first filial generation
  96. F2 generation
    second filial generation
  97. alleles
    alternative versions of a gene
  98. Mendel's Model (1-4)
    • 1. alternative versions of genes account for variations in inherited characters
    • 2. for each character, an organism inherits two copies of a gene, one from each parent
    • 3. if the two alleles at a locus differ, then one, the dominant allele, determines the organism's appearance; the other, the recessive allele, has no noticeable effect on the organism's appearance
    • 4. the two alleles for a heritable character segregate (separate from each other) during gamete formation and end up in different gametes
  99. Law of Segregation
    the two alleles for a heritable character segregate (separate from each other) during gamete formation and end up in different gametes
  100. homozygous
    an organism that has a pair of identical alleles for a character will be homozygous for the gene controlling that character
  101. heterozygous
    an organism that has two different alleles for a gene is heterozygous for that gene
  102. phenotype
    an organism's observable traits, or appearance (includes physiological traits, like non-pollenation) (purple flower)
  103. genotype
    an organism's genetic makeup (PP, Pp or pp)
  104. testcross
    breeding an organism of unknown genotype with a recessive homozygote. This can reveal the genotype of that organism. Developed by Mendel
  105. monohybrids
    heterozygous for the one particular character being followed in the cross. Cross between them is a monohybrid cross
  106. dihybrids
    individuals heterozygous for the two characters being followed in the cross (F1 group). Cross between them is a dihybrid cross.
  107. law of independant assortment
    each pair of alleles segregates independantly of each other pair of alleles during gamete formation. (Only works with non-homologus chromosomes or very far apart on same chromosome)
  108. multiplication rule
    to determine a probability, multiply the probability of one event by the probability of the other. (coin will land heads up is 1/2 x 1/2 = 1/4)
  109. addition rule
    the probability that any one of two or more mutually exclusive events will occur is calculated by adding their individual probabilities
  110. complete dominance
    when one trait completely controls the phenotype of an organism (purple flowers). The dominant homozygote and the heterozygote are indistinguishable.
  111. incomplete dominance
    when traits blend in the heterozygote (pink snapdragons)
  112. codominance
    two alleles each effect the phenotype in separate, distinguishable ways.
  113. dominant
    seen in phenotype
  114. multiple allele dominance
    when multiple alleles of a single gene determine a trait. Blood type (IA, IB, i)
  115. pleiotropy
    when 1 gene has multiple phenotypic effects (CF--multiple symptoms)
  116. epistasis
    the phenotypic expression of a gene at one locus alters that of a gene at a second locus. Or, when two completely unrelated genes control phenotype (Labrador Retrievers--gene for color and a gene for depositing that color in the coat. Deposition is epistatic to the gene that codes for black/brown)
  117. polygenic inheritance
    more than one incompletely dominant gene controls phenotype (skin color)
  118. quantitative characters
    when characters cannot be classified because they vary in the population in gradiations along a continuium
  119. norm of reaction
    when a genotype is associated with a range of phenotypic possibilities rather than a rigidly defined phenotype, due to environmental influences.
  120. multifactorial
    many factors, both genetic and environmental, collectively influence phenotype
  121. pedigree
    family tree describing the traits of parents and children across generations
  122. carriers
    heterozygotes who can transmit a recessive allele to to their offspring
  123. cosanguineous matings
    "same blood"--incestiuous. More likely to produce recessive allele
  124. cystic fibrosis
    (European descent) thicker and stickier mucus, building up in pancreas, lungs, disgestive tract and other organs, leading to multiple (pleiotropic) effects, including poor absorption of nutrients from the intestine, chronic bronchitis, and recurrent bacterial infections
  125. sickle-cell disease
    (African descent) low oxygen will cause RBCs to form sickle-shape, clogging blood vessels, causing physical weakness, pain, organ damage and paralysis. Codominant allele. Being heterozygous for sickle-cell reduces malaria attacks.
  126. achondroplasia
    dominant-allele disorder. Lethal dominant allele--AA's die before birth. Dwarfism. Most of the population is homozygous for the recessive allele.
  127. Huntington's Disease
    degenerative lethal nerve disease, no effect until 35-45 years old, so transmits to children before showing signs. One of few dominant lethal that can be passed on.
  128. multifactorial disorders
    disorders that have a genetic component and an significant environmental influence. Heart disease, diabetes, cancer, alcoholism, schitzophrenia, bipolar disorder,
  129. amniocentesis
    14-16th week of pregnancy, extracts amniotic fluid, do a karyotype and perform tests for disorders.
  130. chorionic villus sampling (CVS)
    inserts a tube through the cervix into the uterus and suctions off a sample of tissue. Perform karyotyping. Can be done it 8th-10th week of pregnancy and can do a rapid analysis
  131. ultrasound
    bounce sound waves off the baby to make a picture
  132. fetoscopy
    needle-thin tube of fiberoptics and camera are put into the uterus
  133. What Mendel did right
    • started with true-breeding plants
    • followed traits for generations
    • used LOTS of samples and experiments--quantitative
  134. cytoplasmic inheritance
    DNA in mitochondria--comes from mom only. Doesn't get mixed up--only changes by mutation/ancestry
  135. chromosome theory of inheritance
    Mendelian genes have specific loci along chromosomes and it is the chromosomes that undergo segregation and independant assortment
  136. Morgan
    Fruit Fly guy (sex linkage)
  137. wild type
    phenotype for a character most commonly observed in natural populations (dominant)
  138. sex-linked gene
    a gene located on either sex chromosome. Y-linked (few genes, few disorders, passed directly from father to son) or X-linked (lots of genes, different pattern of inheritance), respectively.
  139. duchenne muscular dystrophy
    1/3500 males. progressive weakening of muscles and loss of coordination. Fatal in early 20s, usually. Gene on X chromosome
  140. hemophilia
    x-linked recessive disorder. Absense of proteins required for blood clotting. (Queen Victoria was a carrier).
  141. color-blindness
    x-linked recessive disorder. Many more men than women afflicted
  142. Barr body
    inactivated X chromosome, usually in women. Most barr-body genes are not expressed. Reactivate in ovaries before meiosis. Which X becomes a barr body is random and independant (mosaic, like a calico)
  143. linked genes
    found near eachother on same chromosome, so tend to be inherited together
  144. genetic recombination
    the production of offspring with combinations of traits that differ from those found in either parent
  145. parental types
    phenotypes that match parental type
  146. recombinant types or recombinants
    nonparental phenotypes (50% in genes that are not linked)
  147. genetic map
    ordered list of genetic loci along a particular chromosome
  148. linkage map
    genetic map based on recombination frequencies
  149. nondisjunction
    members of a pair of homologous chromosomes do not move apart properly during meiosis I or sister chromatids fail to separate during meiosis II
  150. aneuploidy
    "not true chromosome number" zygote will have an abnormal number of chromosomes
  151. monosomic
    2n-1 if aneuploid is missing an allele it is monosomic for that chromosome
  152. trisomic
    2n+1 if aneuploid has an extra allele it is trisomic for that chromosome
  153. polyploidy
    more than two complete chromosomal sets in all somatic cells (triploidy 3n or tetraploidy 4n). Common in plants
  154. deletion
    when a chromosomal fragment is lost (errors in meiosis or radiation). More likely during meiosis
  155. duplication
    when a chromosomal fragment is repeated (maybe stuck on from a deleted section in another sister chromatid) Can also stick onto a homologous chromosome, so duplicated sections might not be identical. More likely during meiosis
  156. inversion
    chromosomal fragment could reattach to the original fragment in the reverse orientation
  157. translocation
    chromosomal fragment could join a nonhomologous chromosome
  158. Down syndrome (trisomy 21)
    1/700 children. extra chromosome 21 (2n=47). characteristic facial features, short stature, correctible heart defects and developmental delays. Some sexually underdeveloped and sterile. Older mom ups the chances. pronounced palm crease in infants. Mongoloidism
  159. Kleinfelter syndrome
    XXY. 1/500 - 1/1000 live male births. Testes are small, male is sterile, some female body characteristics, low intelligence. 2n=47
  160. XYY
    en=47 Sterile. Men are taller than normal. Not too smart, tall and skinny, bad acne, thick glasses
  161. XXX
    1/1000 female live births. healthy and a little taller than normal. at risk of learning disabilities but are fertile. 2n=47
  162. Turner Syndrome
    X0 1/2500 female births. Only known monosomy in humans. sterile. normal intelligence. Webbing of neck. 2n=45
  163. genetic imprinting
    variation in phenotype depending on whether an allele is inherited from the male or female parent
  164. extranuclear genes or cytoplasmic genes
    genes from sources outside the nucleus (mitochondria and chloroplast)
  165. why are humans hard to study?
    • same life span as scientists
    • don't produce enough children to test ratios
    • can't make people breed to answer questions
  166. three things that cause problems at birth
    • genetic disease (CF, Sickle-Cell--recessive)
    • chromosomal abnormalities (aneuploidy-deletion, duplication, inversion, translocation)
    • In-utero poisoning (alcohol, thalidomide)