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2011-10-10 02:29:50

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  1. _____ died of cancer in 1951, but biologist have kept her cancer cells alive ever since.
    Henrietta Lacks
  2. In five minutes our bodies will produce __________ new cells.
    10 billion
  3. Transcription
    produces three different types of RNA molecules
  4. Information flows from DNA to RNA during ______ and from RNA to protein during ______
    • transcription
    • translation
  5. RNA differs from DNA in that it contains the sugar _____ and the base _______
    • Ribose
    • Uracil
  6. Transposon
    The jumping genes that can move around the genome and sometimes inactivate other genes
  7. A virus that infects bacterium is called a ________
  8. Viruses that break open and kill their host cells upon release are called ________ viruses
  9. Viruses that use reverse transcriptase are called _____
  10. In addition to the nucleus, what other organelles contain DNA?
    • Mitochondria
    • Chlorophasts
    • both B and C
  11. The greatest difference between ancient and modern biotechnology methods is the _______
    • level of precision
    • rapidity with which organisms can be altered
    • the ability to transgress species boundaries
  12. The enzyme ______ can link together two pieces of DNA from different sources to produce recombinant molecules
    DNA ligase
  13. Transgenic pigs, cows, and sheep are created by adding engineered genes
    to an externally fertilized zygote
  14. The hereditary disorder ________ results in the production of abnormal red blood cells
    Sickle cell anemia
  15. List, in the correct order, the phases of mitosis
    Prophase, Metaphase, Anaphase, Telophase
  16. Which of the following is not a benefit of sexual reproduction?
    Increased genetic diversity
    Energy conservation
    Greater likelihood that some offspring will survive
    Greater chance the species can survive in a changing environment
    Energy conservation
  17. Which of the following are haploids?
    Somatic cells
    All of these
  18. Hybrids are of what genotype?
  19. When examining a single gene, what is the predicted genotypic ratio in the F2 generation if two F1 hybrids are crossed?
  20. In a testcross, an individual of unknown genotype is crossed with an individual of which genotype?
    Homozygous recessive
  21. Inversion
    A mutation in which a segment of DNA is flipped 180 degrees
  22. After DNA replication
    Each DNA molecule is composed of one parent and one daughter strand (semiconservative)
  23. During DNA replication, what enzymes links the individual nuclotides together to form the new DNA strands?
    DNA polymerase
  24. What role does DNA ligase play in making recombinant DNA?
    It joins the DNA fragments together
  25. Which of the following would a researcher use to cut eukaryotic DNA at a particular sequence?
    Restriction enzyme
  26. For a gene to be expressed in all cells in an animal, the transgenes is put into
    The zygote
  27. Which of the following has a major effect on phenotype?
    Amount of noncoding DNA
    Length of RFLPs
    • Environment
    • Genotype
    • Both B and C
  28. Which of the following would be considered a chromosomal mutation?
    • All of the above
    • Duplication
    • Deletion
    • Translocation
    • Inversion
  29. A lytic infection differs from lysogenic viral infection in that ONLY the lytic does the virus ________
    Ruptre the cell soon after infection
  30. If meiosis did not occur in sexually reproducing organisms ______
    Growth of the zygote would be halted
    Mitosis would be suffcient
    Gametes would be haploid
    The chromosome number would double in each generation
    Eggs would be haploid, but sperm would be diploid
    The chromosome number would double in each generation
  31. Through meiosis
    • alternate forms of genes are shuffled
    • parental DNA is divided and distributed to forming gametes
    • the diploid chromosome number is reduced to haploid
    • offspring are provided with new gene combinations
    • all of the above
  32. Crossing over
    Alters the composition of chromosomes and results in new combinations of alleles being channeled into the daughter cells
  33. Which organisms did Mendel utilize to work out the laws of segregation and independent assortment?
    The garden pea
  34. A testcross involves
    an F1 hybrid and an organism that is homozygous recessive for that trait
  35. The major advantage of sexual reproduction to the population of an organism over asexual reproduction is that ______
    Sexual reproduction produces greater genetic diversity
  36. When an organism has two different alleles of the same gene it is said to be
  37. The operation of natural selection depends upon the fact that _______
    Some individuals have a better chance to produce more offspring
  38. Atificial selection occurs when _______
    Humans determine which organism will survive
  39. Some dogs have erect ears; others have drooping ears. Some dogs bark when following a scent; others are silent. Erect ears and barking are homozygous for both domninat traits is mated to a droopy-eared,silent follower. The phenotypic ratio expected in the F1 generation is _______
    100 percent of one phenotype
  40. Normal cervical cells---nucleus is small
    Pre-cancerous cevical cells---nucleus is larger
    Cancerous cevical cells---nucleus is largest
  41. Mitosis
    • the cell copies its DNA then divides in two
    • allows growth and cell replacement in multicelled organisms and creates new individuals in single-celled organisms
    • before cell division, it copies DNA
  42. In 1889, the German bilogist _______ insisted that the nucleus contained the hereditary material which he called the ______.
    • August Weismann
    • germ plasm
  43. We can describe the process of cell reproduction in terms of the three Ms
    • Materials---the small molecules that carry energy or serve as building blocks
    • Machinery---the organelles and macromolecular structures needed to carry on cellular processess including DNA
    • Memory---the information contained in the nuclear DNA
  44. Before a cell divides it usually double its _____
    • materials
    • machinery
    • memory
  45. Weismann wrote, Heredity is brought about by the transference from one generation to another, of a substance with a definite...molecular constitution
  46. How do prokaryotic (no nucleus) cells divide
    • Binary fission
    • DNA that is formed in a closed loop
  47. Bacteria divide by binary fission in a process that does not involve mitosis
  48. Homologous chromosomes
    pairs of matching chromosomes
  49. After the first growth phase (G1) the DNA doubles (S). The cell then increases materials (G2) in prepartion for the seperation of identical chromatids (mitosis) and the seperation of the two daughter cells (cytokinesis.)
  50. Homolog
    Each member of the chromosomes pair
  51. 1. mitosis---the division of the nucleus
    2. cytokinesis---the division of the cytoplasm and formation of two seperate plasma membranes
    3. interphase---the time when the DNA replicates and the cells grow
    Cell Cycle
  52. Interphase includes three parts
    • G1, the gap or growth phase, between the completion of M and the beginning of DNA synthesis
    • S, the period of DNA synthesis when a cell copies its chromosomes
    • G2, the gap between the completion of DNA synthesis and the beginning of M
  53. Chromatid
    • one of the two seperate but connecte bodies that make up a chromosomes at the beginning fo mitosis, when the chromosomes first become visible
    • a chromatid contains a single long molecule of DNA
  54. Centromere
    the two chromatids are joined at a strech of DNA
  55. Interphase
    The uncoiled chromosomes replicate.
  56. Prophase
    The chromosomes condense and the nuclear membrane breaks up
  57. Metaphase
    The chromosomes line up along a central plane of the cell and the asters become visible
  58. Anaphase
    Spindle fibers pull the chromatids to opposite ends of the cell
  59. Telophase
    Two new nuclear membranes appear, the asters disintegrate, and the chromosomes uncoil, again becoming invisible
  60. Microtubles ________
    • ______
    • _______
    • ________
    • Proteins that help out with microtubles are actin and myosin
  61. Microtubles
    hollow tubes made of the protein tubulin
  62. Telophase
    the last phase of mitosis, the mitotic apparatus breaks down. The chromosomes unwind, and the distinctive bar or string shapes are no longer visible with a microscope
  63. Cytokinesis
    splitting of cells
  64. 1. the movement of the chromosomes toward the equator to form the metaphase plate
    2. the movement of the separated chromatids toward the poles
    3. the movement of the spindle poles away from each other during prophase and again during anaphase
    The major players are the microtubles
  65. Microtubles move the chromosomes by attaching to the chroatids and growing or shortening
  66. Histones
    • A set of small, positively charged proteins
    • Aid of specialized proteins----the most adundant of which is histones
    • Most cells have five types of histones
  67. Nucleosome
    Two wraps of DNA and a length of DNA linking to the next bead
  68. Chromosome banding
    a striped pattern visible in a light microscope because dyes darken each band a little differently
  69. Animal cells actin filaments form a contractile ring that pinches the cytoplasm in two. In plant cells telophase includes the building of new cell membranes and cell walls between the two daughter cells
  70. 1. The cells stop dividing during G1 when they run out of free space on which to spread, that is, when neighboring cells all touch each other
    2. cells that have proceeded beyond G1 begin to divide when contact with their neighbors ceases
    Contact inhibition
  71. 1. In cell cultures, normal cells divide until they form a single, continuous layer of cells, then stop.
    2. If we scrap a "wound" in this monolayer of normal cells, cells from the edge move into the open space and divide until the wound is filled
    3. Normal cells stop dividing when they come into contact with other cells
    4. Cancer cells do not self regulate in this way Instead they conintue to divide even after they come into contact with other cells, piling up on top of one another
  72. Meiosis
    cells produce daughter cells (eggs and sperm) with only half the normal number of chromosomes
  73. Genetics
    The study of inheritance
  74. Transmission genetics
    the study of how variation is passed from one generation to the next
  75. Molecular gentics
    the study of DNA carries genetics instructions and how cells carry out these instructions
  76. Phenotype
    encompasses both physical and behavioral characterstics
  77. Genotype
    Particular collection of genes of a cell or organisms
  78. Four important points underlie the universiality of genetic inheritance in eukaryotes
    • 1. All cellular organisma use DNA as the genetic material
    • 2. The DNA of all eukaryotic organisms is organized into chromosomes
    • 3. Almost all chromosomes exist in pairs at some time during a sexual life sycle
    • 4. These pairs of chromosomes behave in the same ways during meiosis and at fertilization
  79. Phenotypic plasticity
    frogs eating each other then growing lungs
  80. Diploid
    Cells that contain paired sets of chromosomes
  81. Gametes
    An organism that reproduces sexually passes the half-set of chromosomes to its offspring in specialized reproductive cells
  82. Haploid
    Each gamete is haploid that it carries a single set of chromosomes----in humans 23
  83. Syngamy
    or ferilization, the union of the two haploid gametes (one from each parent) to form a single diploid cell called a Zygote
  84. Crossing over
    At the very beginning of meiosis, during prophase I, homologous chromatids pair up in synapis. While they are paired up, the chromatids may break at places called chiasma and exchange equivalent pieces. The result is new combinations of genes on each chromatid
  85. All kids can be different because of crossing over
  86. Down Syndrome
    • Extra chromosome Number 21
    • Has 47 instead of 46
  87. Trisomy 21
    The presence of three rather than two, copies of chromsome 21
  88. Nondisjunction
    Occasionally separation of homologous in anaphase I and chromatids in anaphase II fails to occur
  89. Down syndrome
    a disorder that leads to mental retardation and the abnormal development of the face
  90. Water flea Daphnia
  91. The X and Y chromosomes are called sex chromosomes. The rest of the chromosomes are called autosomes.
    A human cell has 22 pairs of autosomes and 1 pair of sex chromosomes
  92. Alleles
    Alternate versions of the same gene
  93. A human cell has 22 pairs of autosomes and 1 pair of sex chromosomes
  94. 44 autosomes chromosomes
    2 sex chromosomes
    46 total
  95. chemidophorus
    species in desert that has no males--only females
  96. Chemidophorus by parthenogenesis
    Female lays deployed egg basically cloning
  97. Homozygous
    • If an individual has two copies of the same alleles
    • TT tt
  98. Heterozygous
    • If an individual has two different alleles of a gene
    • Tt
  99. Cross breeding
    method of breeding two genetically distinct organisms
  100. Gregor Mendel
    father of genetics
  101. Dominant
    when it alone determines the phenotype of a heterozygote
  102. The seven traits of peas
    • Seed shape
    • Pod shape
    • Seed color
    • Pod color
    • Flower color
    • Flower position
    • Stem length
  103. Recessive
    when it contributes nothing to the phenotype of a heterzygote
  104. monohybrid cross
    only concerned with one trait
  105. Incomplete dominance
    both alleles are expressed
  106. Pea flowers carry both male and female parts
  107. Principle of segregation
    Each sexually reproducing organisms has two genes for each characterisic; these two genes segregate (or seperate) during the production of gametes
  108. Backcross
    Instead of allowing F1 heterozygotes to self-pollinate, he crossed them with the homozygous recessive stock
  109. Monohybrid 3:1
  110. Dihybrid Cross 9:3:3:1
  111. Principle of independent assortment (proven false later)
    Each pair of genes is distributed independently from every other pair during the formation of the gamtes
  112. Walter Sutton's six rules of inheritance
    • 1. Chromosomes come in pairs. One chromosomes comes from the mother and one from the father. We now call these "homologous" pairs
    • 2. Synapsis is the pairing of homologous maternal and paternal chromosomes. These pairs seperate into different daughter cells during meiosis
    • 3. The chromosomes are not broken down and created anew during each cell cycle
    • 4. The chromosomes carry genes
    • 5. Meiosis createsnew combination of genes in each generation. During meiosis either homolog may end up in either new cell, reguardless of the way all the other homologous chromosomes divide. The accounts for Mendels's principle of segeration
    • 6. Each chromosome carries a different set of genes, and all of the genes on one chromosomes are inherited together. That different chromosomes are inherited independently accounts for Mendel's principle of indeperdent assortment
  113. Crossing over is the physical exchange of material between homologous chromosomes.
  114. The chance that any two genes on a chromosome will recombine is proportional to the physical distance between them
  115. Four bases:
    • Purines: Adenine (A) and Guanine (G)
    • Pyrimidines: Cytocine (C) and Thymine (T)
  116. Sugar-phosphate backbone
  117. HA oxidase (Homoaxidary Acid)
    Enzyme that helps breaks down HA
  118. alkaptonuria
    inherited disease that causes urine to turn black when parents were first cousins
  119. Heploid
    Only 1st set of chromsomes
  120. George Beadle and Edwared Tatum chsoe to study a simple fungus, the pink bread mold Neurospora
    Their work suggested that every gene somehow affects the function of a single enzyme
  121. Sickled and standard red blood cells
    • 1 in 165 have two copies of the allele and have the disease
    • RBC live 120 days
    • SBC live 40 days
  122. Sickle cells have resistance against malaria
    75% protected
    25% unprotected
    Sickle cells comes from the cresent of sickle shape of the red blood cells
  123. Bacteriophage
    Phages are a kind of virus that infect bacteria. Viruses are assemblies of protein and DNA capable of forcing host cells to make more viruses
  124. Life cycle of a phage
    • 1. Phage attaches to surface of bacterium
    • 2. Phage injects its DNA into bacterium
    • 3. DNA inside bacterium
    • 4. Phage DNA directs host cell to produce new phage proteins and phage DNA
    • 5. Complete, mature phages assemble
    • 6. Cell wall bursts, releasing 100 to 200 new phages
  125. Viruses never have both DNA and RNA---they have one but not both
  126. In the Hershey-Chase experiment, radioactive DNA from a phage shows up inside the infected bacterium. Radioactive protein stays outside. This 1952 experiment finally convinced bilogist that DNA not prtein, was the gentic material (later work showed that a few viruses use RNA as their genetic material)
  127. According to this model, DNA replication is semiconservatice. That is half of each parent molecule is present in each daughter molecule. Each new DNA molecule is really only half old and half new
    (proven wrong)
  128. DNA replication is semiconservative; when DNA replicares, each half of the double helix acquries a new mate
  129. At one time the biologist thought that DNA replication was conservative. Both halves of the old molecule stayed together while the whole new molecule was created.
    In fact DNA replicates, each half of the old double helix acquires a new mate.
  130. 3 enzymes that replicate DNA
    • 1. Helicase
    • 2. Polymerase
    • 3. Ligose
  131. Helicase
    Unwinds DNA
  132. DNA polymerase
    approaches RNA primer and replaces with DNA
  133. DNA ligase
    • connects Okazaki fragments
    • Biological glue
  134. Bacteria
    Not a double helix but circular DNA
  135. Replication of DNA
    Replication begins at the origin of replication then works in both direction around the circle
  136. Cellmatic--changes just in the cell
    Somatic--gentic material is unchanged
  137. Mutations
    Permanent changes in DNA
  138. The cause of mutations
    Radiation kills genes
  139. Occationally mutations occur because DNA polymerase places the wrong nucleotide in a sequence during the synthesis (S) phase of the cell cycle
  140. Mutagens
    • Increase the rate of mutations.
    • Ultra-violet light, high-energy radiation such asa x-rays and many chemicals can all act as mutagens
  141. Point Mutations
    • Change one or several nucleotide pairs.
    • 1. Base Substitutions
    • 2. Insertion
    • 3. Deletion
  142. Chromosomal Mutations
    • Change relativiely large regions of chromosomes
    • 1. Deficiencies
    • 2. Translocations
    • 3. Inversions
    • 4. Duplications
    • 5. Polyploidy
  143. Base Substitution
    The replacement of one base (nucleotide) by another
  144. Insertion
    The addition of one or more nucleotides
  145. Deletion
    The removal of one or more nucleotides
  146. Deficiencies
    Deletions that are larger than a few nucleotides
  147. Translocations
    In which part one chromosome is moved to another chromosome
  148. Inversions
    In which a segment of a chromosome is flipped 180 degrees
  149. Duplications
    In which part of a chromosome appears twice
  150. Polyploidy (aneuploidy)
    Chromosomes have doubled but cytokenisis didnt happen and there was no cell division
  151. Trisomy
    The presence of three copies of a certain chromosome
  152. Healthy cells are quick to repair damaged DNA
    • 1. Damage caused by UV light
    • 2. Damage is removed by enzyme
    • 3. DNA polymerase creates a new sequence
    • 4. DNA ligase seals the nick
  153. Codon
    A group of three nucleotides that specifies a single amino acid within a polypeptide
  154. Genetic Code
    • Clearly specifies which nucleotide sequences correspond to which amino acid sequences
    • A language with 20 amino acid letters
  155. The genetic code is also said to be universal
    • because all eukaryote orgainisms use the same code.
    • For example, when globin RNA from rabbit red blood cells is added to wheat germ cells, the wheat cells make rabbit globin, demonstrating that wheat cells and rabbit cells use the same genetic code to translate RNA into protein
  156. The protein making machinery of wheat plant can synthesize blood proteins normally found only in rabbits
  157. Francis Crick
    Central dogma of molecular biology: DNA specifes RNA which specifies proteins
  158. DNA specifies RNA which specifies protein. DNA in the nucleus is transcribed into RNA. Outside the nucleus in the cytoplasm, ribosomes traslate RNA into polypeptides.
    In prokaryotes, which lack a nucleus, both transcription occur in the cytoplasm
  159. Messenger RNA (mRNA)
    this is what The RNA copy of the information from DNA is composed of
  160. Transfer RNAs
    The mRNA codons bind to the tRNA not to the amino acid its self
  161. 1. Transcription
    2. Messenger
    3. Transfer
    • 1.messenger- info to ribsome
    • 2. ribosomes- works with ribosomes
    • 3. transfer- brings amino acids to sight of ribosomes
  162. DNA -----________-----RNA------________--------Polypeptide
    • Transcription
    • Translation
  163. Transcriptional control
    when cells increase or decrease the amount of mRNA transcribed from the DNA
  164. Translational control
    A cell varies the rate at which it translates different mRNA
  165. Barbara McClintock
    discovered Transposon
  166. Transposon
    • to describe these genes that jumped around the genome
    • "jumping genes"
    • Point mutations
  167. Mobile Genes
    genes that move around
  168. Plasmids
    can exist as simple loops of DNA sparate from the host cell's DNA--usually in prokaryote or yeast cells---that pass from cell to cell
  169. Virus
    an assemblage of nucleic acid (DNA or RNA) and proteins
  170. Viruses come in many shapes
  171. Protein coat
    Surround the gentic material
  172. Life of a Bacteriophage
    • 1. Phage attached to surface of bacterium
    • 2. Phage injects its DNA into bacterium
    • 3. DNA is inside bacterium
    • 4. Phage DNA directs host cell to produce new viral proteins and DNA
    • 5. Complex, mature phages assemble
    • 6. Cell wall bursts, releasing 100 to 200 new phages
  173. The life of a phage
    A phage attached to the surface of its bacterial host and injects its DNA inside. The host cell transcribes and translated the phage genes to make more phages, which eventually burst from and kill the host cell
  174. Viruses have two ways to duplicate
    • 1. Autonomous replication
    • 2. Intgrated replication
  175. Autonomous replication
    the genes are separate from the DNA of the host cell and can replicate even when the host DNA is not replicating
  176. Integrated replication
    The genes become integrated into the hosts DNA and are replicated along with those of the host
  177. Episomes
    Viruses and plasmids that switch back and forth between integrated and autonomous replication
  178. Plasmid
    A small piece of circular DNA or RNA in a bacterial or yeast cell that included from 3 to 300 genes
  179. Conjugation
    Two bacteria temporarily attach to one another and exchange genetic meterial
  180. Conjugation
    These genes encode an enzyme that makes the cell reisistant to an antibiotic
  181. Transposase
    Enzyme which inserts the transposon into new places
  182. complex transposons
    lie near each other on the host genome, they jump together carrying with them any genes that lie between them
  183. Viruses that cause tumors are a special case
    tumor viruses multiply only when their eukaryotic host do
  184. DNA tumors viruses integrate thier DNA into the DNA of eukaryotic cells. Then disrupt the cell cycle forcing t=infected cells into excessive cell division resulting in growth of a tumor
  185. Lytic Cycle
    DNA is separate from that of its host a lyses its host
  186. The prophage and the lytic cycle together make up the viral ___________
    Lysogenic cycle
  187. Lysogenic cycle
    • 1. Phage DNA enters host cell
    • 2. Phage DNA integrates into host cell DNA
    • 3. Phage DNA replicates along with bacterial DNA
    • 4. Cycle repeats
  188. Lytic Cycle
    • 1. Bacterium makes new phage DNA and protien
    • 2. Bacterium assembles new pages
    • 3. Cell burst releasing new phages
  189. Reverse transcriptase
    Copies RNA into DNA
  190. T cell
    HIV virus bind to T cell and only cell in body
  191. How retroviruses reproduce
    • 1. Retrovirus membrane fuses with host cell membrane
    • 2. Viral coat breaks up
    • 3. Reverse transcriptase makes complementary single strand of DNA
    • 4. Host cell makes complememtnray copy of DNA which integrates into host cell DNA
    • 5. Host cell transcribes viral DNA into mRNA
    • 6. Host cell translates viral RNA into viral proteins
    • 7. Viral proteins and RNA assemble
    • 8. Host cell releases new retrovirus
  192. AIDS has RNA but no DNA
  193. Over evolutionary time, viruses could have evovled either from free-living cells or from transposons
  194. AZT increases the number of proteins in the body so ammune sstem stays normal
  195. Mitochonria and cholorplast which have their own DNA separate from the nuclear DNA evolved when a prokaryote ancestor came to live in symbiosis with another cell. The gentic systems of mitochondria and chloroplasts differ from those in both eukaryotic nuclear DNA and in prokaryotes suggesting that these organelles have an ancient and separate origin