Bio 101 Exam 3 Cards

  1. DNA (deoxyribonucleic acid)
    Contains the genetic material for the function and development for all living organisms

    each strand is unique and can be found in hair, blood, dead skin cells and bodily fluids
  2. Nucleic acids, and nucleotides
    • Nucleic Acids - macromolecule that stores information
    • Nucleotides - individual units of nucleic acid
  3. Base pairs
    • DNA bases are paired with hydrogen bonds 
    • Adenine always pairs with Thymine 
    • Guanine always pairs with Cytosine 
  4. Genome
    The organisms complete set of DNA, in eukaryotes this can be found in the nucleus of almost every cell
  5. Chromosomes
    One or more pieces of unique DNA that make up an organism's genome, consist of hundreds of millions of base pairs
  6. Gene
    • The sequences of base in the DNA that create a code for the construction a functional product
    • Alleles - alternative versions of a gene for the same feature
    • Trait - any single characteristic of an organism
  7. Coding vs. Non coding regions
    • Coding - gene sequences
    • Non coding - bases that do not code for anything and demonstrate no purpose
  8. Introns
    Non coding regions within gene sequences
  9. Why do organisms have non coding regions?
    • may encode short RNA molecules that may have a certain function in gene regulation
    • may act as a reservoir for potentially useful sequences
  10. Genotype and Phenotype
    • Genotype - all of the genes contained in an organism 
    • Phenotype - the physical manifestations of the instructions from the gene
  11. Transcription and Translation
    • Transcription - when a DNA sequence is copied from DNA to mRNA
    • Translation - the sequence for a gene, now encoded in the mRNA, is used for the direction of the production of protein
  12. 4 Parts of Transcription
    • Recognize and Bind
    • Transcribe
    • Terminate
    • Capping and Editing
  13. Recognize and Bind
    RNA ploymerase recognizes the promoter of site and and binds onto DNA strand, the promoter site tells the RNA polymerase to start here
  14. Transcribe
    • RNA polymerase processes the DNA strand to build a single strand copy of the gene and has 4 nucleotides: adenine, uracil, guanine, cytosine
    • T-----A
    • A-----U
    • G-----C
    • C-----G
  15. Terminate
    Polymerase stops the transcription and releases the mRNA transcript when it encounters a termination code, signalling end of the gene
  16. Capping and editing
    The cap and tail are added the mRNA for protection and allow the protein making machinery to recognize the mRNA
  17. Translation
    The mRNA is translated by ribosomes using amino acids to transfer RNA that is found in the cytoplasm
  18. Translating ingredients in the cytoplasm
    Amino acids, Ribosomes, and tRNA
  19. Three parts of Translation
    • Recognize and Initiate Protein Building
    • Elongate
    • Termination
  20. Recognize and Initiate Protein Building
    mRNA is recognized by tRNA and Ribosomes, starting sequence is the AUG Codon, AUG Codon then creates methionine. tRNA site binds to the mRNA starting sequence, then ribosomal units assemble around mRNA
  21. Elongate
    Ribosomes travel along the strand of mRNA and attract the tRNA carrying the appropriate amino acids, tRNA then bonds to the codon. Ribosomes take tRNA and attach it to the protein chain - protein synthesis. The empty tRNA then detaches and floats off in the cytoplasm
  22. Terminate
    the protein making process is complete when the ribosomes encounters the stop codon, then releases the protein into the cytoplasm.
  23. Gene expression and regulation
    • expression - is transcription and translation
    • regulation - is positive and negative control
  24. Gene Regulation
    cells control gene expressions with transcription factors which are proteins that bind to specific regulatory sites on the DNA
  25. Positive versus negative control
    • Positive - transcription factor initiates or speeds up gene expression when bound to the regulatory site
    • Negative - transcription factor slows or stops gene expression bound to the regulatory site
  26. Operon
    • group of several genes and elements that control their gene expression as a unit has three parts:
    • Promoter
    • Operator
    • Regulatory Gene
  27. Promoter
    • specific nucleotide sequence in the DNA that signals the beginning of a gene
    • RNA polymerase recognizes and binds to the promoter region of gene that is to be transcribed
  28. Operator
    • the regulatory portion of the DNA
    • repressor protein binds to the operator and blocks the RNA ploymerase from transcribing the genes for lactose metabolism
  29. Regulatory Gene
    codes for the repressor protein, when bound to the operator region, blocks the RNA polymerase from binding the promoter site
  30. When glucose is absent, but lactose is present
    • an activator helps unwind the DNA near the Iac operon
    • RNA polymerase binds to the DNA and transcribe the gene
  31. When glocuse is present, regardless of whether or not lactose is present
    • an activator can not bind to the DNA 
    • RNA polymerase is prevented from binding to and transcribing the lactose metabolism genes to the DNA
  32. Mutation
    an alteration in the base pair sequence of an individual's DNA, may arise spontaneously or following exposure to a mutagen, most mutations are neutral
  33. Gamete cells vs. somatic cells
    • Mutations in sex cells can be passed from parent to offspring, leading to miscarriage or birth defects
    • Mutations in non sex cells can have bad health consequences only for the person carrying them
  34. Point mutations
    one base pair is changed in the DNA
  35. Chromosomal Abberations
    Changes to the overall organization of the genes on the chromosome
  36. Causes of mutations
    • Spontaneous mutations - accidental errors occur during the DNA duplication process during cell division
    • Radiation - induced mutations - radiation with enough energy disrupts atomic structure of DNA, breaking apart chromosomes 
    • Chemical induced mutations - chemicals that can react with the atoms in the DNA molecules
  37. Prokaryotic Cells
    DNA is in a single, circular chromosome. Attached at one site to the cell membrane, and has binary fission
  38. Eukaryotic Cells
    animal cells, DNA is in free-floating linear chromosomes within the nucleus, has cell cycle
  39. Binary Fission
    Asexual reproduction, parent cell splits into two new genetically identical daughter cells
  40. Cell cycle
    • alterations of activities between processes related to growth and cell division
    • somatic cells-cells forming the body of the organism
    • reproductive cells-sperm and egg cells in humans
  41. Two phases of Cell Cycles
    • interphase-cell grows and prepares to divide
    • mitotic phase-DNA and cellular organelles divide
  42. Three phases of Interphase
    • Gap 1 - primary growth phase 
    • synthesis - prepares for division, then chromosome replication
    • Gap 2 - secondary growth period, preparation for cell division
  43. Two stages of Mitotic Phase
    • Mitosis-parent cell's nucleus divides, along with duplicated chromosomes, enables cells to generate new, genetically identical cells
    • Cytokinesis-cytoplasm divides single parent cell into two new daughter cells, each new cell has own set of DNA
  44. Four Steps of Mitosis
    • Prophase-nuclear membrane breaks down, sister chromatids condense, spindle forms in cytoplasm
    • Metaphase-sister chromatids line up at the center of the cell
    • Anaphase-spindle fibers pull apart the sister chromatid pairs at the centromeres, two sets go to other sides of the cell
    • Telophase- chromosomes begin to uncoil, nucleus reassembles around the chromosomes, parent cell begins to pinch apart
  45. Cytokinesis
    cytoplasm divides into two new daughter cells, duplicated cellular organelles are divided between the cells
  46. Apoptosis
    pre-planned process of cell suicide, cells targeted for apoptosis usually involve organs that are almost constantly in contact with harmful substances
  47. Cancer
    unrestrained cell growth and division that can damage adjacent tissues
  48. Two tumors
    • Benign-remain localized and stay in one place
    • Malignant-spread to other locations in the body via bloodstream
  49. Three features of cancer
    • cancer cells lose their contact inhibition
    • cancer cells can divide indefinitely
    • cancer cells have reduced stickiness
  50. Treatments for cancer
    remove or kill rapidly dividing cells, surgery by removing the tumor, chemotherapy, or radiation
  51. Diploid cells
    46 chromosomes, found in somatic cells, cells that make up the organism
  52. Haploid cells
    23 chromosomes, found in reproductive cells, sperm and eggs, product of meiosis
  53. Two purposes for Meiosis
    reduces the amount of genetic material in reproductive cells, and creates reproductive that are all different from each other with respect to combinations of alleles they carry
  54. Interphase
    chromosomes replicate in preparation for meiosis
  55. prophase 1
    • replicated chromosomes condense, sister chromatids crossover, nuclear membrane disintegrates.
    • Maternal and paternal chromosomes swap little bits of DNA
  56. Metaphase 1
    homologues move toward the center of the cell and line up
  57. Anaphase 1
    Homologues separate and are pulled to opposite poles by the spindle fibers
  58. Telophase 1 and cytokinesis
    sister chromatids arrive at the cell poles, nuclear membrane reassembles around them, cell pinches into two daughter cells, chromsomes may unwind slightly
  59. interphase
    a brief interphase prior to prophase 2, chromosomes are not replicated
  60. Prophase 2
    chromosomes in daughter cells condense, spindle fibers form
  61. Metaphase 2
    sister chromatids pairs line up at the center of the cell
  62. Anaphase 2
    sister chromatids are pulled apart by the spindle fibers toward the opposite cell poles
  63. Telophase 2 and Cytokenisis
    chromosomes uncoil, cells pinch into 4 haploid daughter cells
  64. Two ways that organisms and cells can reproduce
    • mitosis and asexual reproduction via binary fission
    • meiosis and sexual reproduction
  65. Asexual reproduction pros and cons
    • pro-fast and efficient
    • con-genetically identical offspring
  66. Sexual reproduction pros and cons
    • Pro-offspring are genetically different from sibling and parents
    • Con-takes more time and energy occur, which can be risky
  67. Sexual reproduction is accomplished by...
    • combining two alleles from two parents at fertilization
    • crossing over during the production of gametes
    • shuffling and assortment of homologues during meiosis
  68. Sexual determination
    sex chromosomes carry information that directs a growing to develop as a male or a female
  69. Methods to determine the sex of an animal or plant
    the presence or absence of sex chromosomes, the number of chromosome sets, environmental factors
  70. Deviation In Chromosome Numbers
    Deviation from normal chromosome number lead to problems, example is down syndrome which has three copies of chromosome 21
  71. Nondisjunction
    unequal distribution of chromosomes that occur in meiosis
  72. Single gene traits
    human traits that are determined by instructions a person carries on a single gene, these traits are straight forward inheritance
  73. Mendel's law of segregation
    during the formation of gametes two alleles for a gene separate, half gametes carry one allele and other half carries the rest
  74. Dominant Trait
    masks the effect of the recessive trait
  75. Recessive trait
    the trait that is masked by the dominant trait
  76. Homozygous
    genotype of a trait for which the two alleles are the same
  77. Heterozygous
    Genotype of a trait for which of the alleles of an individual carries are different from each other
  78. Three ideas of inheritance
    • 1) each parent puts into every egg and sperm it makes a single set of instructions for building a trait
    • 2) offspring receives two copies of the instructions for any trait
    • 3) the trait observed in an individual depends on the two copies of the gene it inherits from its parent
  79. Punnett Squares
    used to determine an individual's genetic makeup
  80. Test Cross
    a mating in which a homozygous recessive individual (aa) is bred with individual of an unknown genotype, showing the dominant genotype
  81. Pedigrees
    used to decipher and predict the inheritance patterns of genes by analyzing which individuals manifest the trait and which do not
  82. Recessive sex linked traits
    affected individuals need not have a parent who exhibits the traits, example is color blindness. Lack a functional copy of a gene that carries out instructions to produce light sensitive proteins that allow people to see the colors red and green
  83. incomplete dominance
    when both alleles of a genotype appear in the phenotype
  84. Co-dominance
    heterozygous offspring display the characteristics of both homozygous parents
  85. Multiple allelism
    a single gene has more than two alleles, example is different blood types A, B, AB, O
  86. Antigens
    proteins that jut out from the red blood cell surface, helps out the immune system
  87. Antibodies
    Molecules in the blood stream that attack foreign antigens
  88. poly-genic traits
    a trait that that is influenced by multiple different genes
Card Set
Bio 101 Exam 3 Cards
DNA and Genetics