Biology 102

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Biology 102
2014-02-09 13:53:58

Chapters 10-12
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  1. Experiments showed that DNA is the genetic material.
    One key experiment demonstrated that certain phages (bacterial viruses) reprogram host cells to produce more phages by injecting their DNA.
  2. DNA and RNA are polymers of nucleotides.
  3. DNA is a double-stranded helix.
    Watson and Crick worked out the three-dimensional structure of DNA: two polynucleotide strands wrapped around each other in a double helix. Hydrogen bonds between bases hold the strands together. Each base pairs with a complementary partner: A with T, G with C
  4. DNA replication depends on specific base pairing.
    DNA replication starts with the separation of DNA strands. Enzymes then use each strand as a template to assemble new nucleotides into a complementary strand.
  5. DNA replication proceeds in two directions at many sites simultaneously.
    Using the enzyme DNA polymerase, the cell synthesizes one daughter strand, as the cell strand is synthesized as a series of short pieces, which are then connected by the enzyme DNA ligase.
  6. The DNA genotype is expressed as proteins, which provide the molecular basis for phenotypic traits.
    The DNA of a gene- a linear sequence of many nucleotides- is transcribed into RNA, which is translated into a polypeptide.
  7. Genetic information written in codons is translated into amino acid sequences.
    Codons are base triplets.
  8. The genetic code dictates how codons are translated into amino acids.
    Nearly all organisms use an identical genetic code to convert the codons of a gene to the amino acid sequence of a polypeptide.
  9. Transcription produces genetic messages in the form of RNA.
    In the nucleus, the DNA helix unzips, and RNA nucleotides line up and hydrogen-bond along one strand of the DNA, following the base-pairing rules.
  10. Eukaryotic RNA is processed before leaving the nucleus as mRNA.
    Noncoding segments of RNA called introns are spliced out, and a cap and tail are added to the ends of the mRNA.
  11. Transfer RNA molecules serve as interpreters during translation.
    Translation takes place in the cytoplasm. A ribosome attaches to the mRNA and translates its message into a specific polypeptide, aided by transfer RNAs (tRNAs). Each tRNA is a folded molecule bearing a base triplet called an anit-codon on one end; a specific amino acid is added to the other end.
  12. Ribosomes build polypeptides.
    Made of rRNA and proteins, ribosomes have binding sites for tRNAs and mRNA.
  13. An initiation codon marks the start of an mRNA message.
  14. Elongation adds amino acids to the polypeptide chain until a stop codon terminates translation.
    As the mRNA moves one codon at a time relative to the ribosome, a tRNA with a complementary anticodon pairs with each codon, adding its amino acid to the growing polypeptide chain.
  15. The flow of genetic information in the cell is DNA- RNA-protein.
    The sequence of codons in DNA, via the sequence of codons in mRNA, spells out the primary structure of a polypeptide.
  16. Mutations can change the meaning of genes.
    Mutations are changes in the DNA nucleotide sequence, caused by errors in DNA replication or recombination, or by mutagens. Substituting, inserting, or deleting nucleotides alter a gene, with varying effects on the organism.
  17. Viral DNA may become part of the host chromosome.
    Viruses can be regards as genes packaged in protein. When phage DNA enters a lytic cycle inside a bacterium, t is replicated, transcribed, and translated: the new viral DNA and protein molecules then assemble into new phages, which burst from the host cell. In the lysogenic cycle, phage DNA inserts into the host chromosome and is passed on to generations of daughter cells. Much later, it may initiate phage production.
  18. Many viruses cause disease in animals and plants.
    Flu viruses and most plant viruses have RNA, rather than DNA,  as their genetic material. Some animal viruses steal a bit of host cell membrane as a protective envelope. Some viruses can remain latent in the host's body for long periods.
  19. The AIDS virus makes DNA on an RNA template.
    HIV is a retrovirus: It uses RNA as a template for making DNA, which then inserts into a host chromosome.
  20. Viroids and prions are formidable pathogens in plants and animals.
    Viroids are RNA molecules that can infect plants. Prions are infectious proteins that can cause brain diseases in animals.
  21. Bacteria can transfer DNA in three ways.
    Bacteria can transfer genes from cell to cell by transformation, transduction, or conjugation.
  22. Bacterial plasmids can serve as carriers for gene transfer.
    Plasmids are small circular DNA molecules separate from the bacterial chromosome.
  23. Scientists have discovered how to put together a bacteriophage with the protein coat of phage T2 and the DNA of phage lambda. If this composite phage were allowed to infect a bacterium, the phages produced in the host cell would have____________.
  24. A geneticist found that a particular mutation had no effect on the polypeptide encoded by a gene. This mutation probably involved ______.
  25. Which of the following correctly ranks the structures in order of size, from largest to smallest?
  26. The nucleotide sequence of a DNA codon is GTA. A messenger RNA molecule with a complementary codon is transcribed from the DNA. In the process of protein synthesis, a transfer RNA pairs with the mRNA codon. What is the nucleotide sequence of the tRNA anticodon?
  27. Describe the process of DNA replication: the ingredients needed, the steps in the process, and the final product.
  28. Describe the process by which the information in a eukaryotic gene is transcribed and translated into a protein. Correctly use these words in your description: tRNA, amino acid, start codon, transcription, RNA splicing, exons, introns, mRNA, gene, codon, RNA polymerase, ribosome, translation, anticodon, peptide bond, stop codon.
  29. Proteins interacting with DNA turn prokaryotic genes on or off in response to environmental changes.
    In prokaryotes, genes for related enzymes are often controlled together in units called operons. Regulatory proteins bing to control sequences in the DNA and turn operons on or off in response to environmental changes.
  30. Chromosome structure and chemical modifications can affect gene expression.
    In multicellular eukaryotes, different types of cells make different proteins because different combinations of genes are active in each type. A chromosome contains DNA wound around clusters of histone proteins, forming a string of beadlike nucleosomes. DNA packing tends to block gene expression by preventing access of transcription proteins to the DNA. One example of DNA packing is X chromosome inactivation in the cells of female mammals. Chemical modifications of DNA bases or histone proteins can result in epigenetic inheritance.
  31. Complex assemblies of proteins control eukaryotic transcription.
    A variety of regulatory proteins interact with DNA and with each other to turn the transcription of eukaryotic genes on or off.
  32. Eukaryotic RNA may be spliced in more than one way.
    After transcription, alternative RNA splicing may generate two or more types of mRNA from the same transcript.
  33. Small RNAs play multiple roles in controlling genes expression.
    MircoRNAs, bound to proteins, can prevent gene expression by forming complexes with mRNA molecules.
  34. Later stages of gene expression are also subject to regulation.
    The lifetime of mRNA molecule helps determine how much protein is mad, as do factors involved in translation. A protein may need to be activated in some way, and eventually the cell will break it down.
  35. Cell signaling and cascades of gene expression direct animal development.
    A series of RNAs and proteins produced in the embryo control the development of an animal from a fertilized egg.
  36. DNA microarrays test for the transcription of many genes at once.
    Scientists can use a DNA microarray to gather data about which genes are turned on or off in a particular cell.
  37. Signal transduction pathways convert message received at the cell surface to responses within the cell.
    A glass slide containing DNA fragments from thousands of genes can be used to test which of those genes are being produced in a particular cell type.
  38. Cell-signaling systems appeared early in the evolution of life.
    Similarities among organisms suggest that signal transduction pathways evolved early in the history of life on Earth.
  39. Plant cloning shows that differentiated cells may retain all of their genetic potential.
    A clone is an individual created by asexual reproduction and thus genetically identical to a single parent.
  40. Therapeutic cloning can produce stem cells with great medical potential.
    The goal of therapeutic cloning is to produce embryonic stem cells. Such cells may eventually be used for a variety of therapeutic purposes. Like embryonic stem cells, adult stem cells can both perpetuate themselves in culture and give rise to differentiated cells. Unlike embryonic stem cells, adult stem cells normally give rise to only a limited range of cell types.
  41. Nuclear transplantation can be used to clone animals.
    In inserting DNA from a host cell into a nucleus-free egg can result in an early embryo that is a clone of the DNA donor. Implanting a blastocyst into a surrogate mother allows for the birth of a cloned mammal.
  42. Cancer results from mutations in genes that control cell division.
    Cancer cells, which divide uncontrollably, result from mutations in genes whose protein products affect the cell cycle. A mutation can change a proto-oncogene, a normal gene that helps control cell division, into an oncogene, which causes cells to divide excessively. Mutations that inactivated tumor-suppressor genes have similar effects.
  43. Multiple genetic changes underlie the development of cancer.
    Cancers result from a series of genetic changes.
  44. Faulty proteins can interfere with normal signal transduction pathways.
    Many proto-oncogenes and tumor-suppressor genes code for proteins active in signal transduction pathways regulating cell division.
  45. Lifestyle choices can reduce the risk of cancer.
    Reducing exposure to carcinogens, which induce cancer-causing mutations, and making other lifestyle choices can help reduce cancer risk.
  46. The control of gene expression is more complex in multicellular eukaryotes than prokaryotes because________.
  47. Your bone cells, muscle cells, and skin cells look different because__________.
  48. Which of the following methods of gene regulation do eukaryotes and prokaryotes have in common?
  49. A homeotic gene does which of the following?
  50. All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs?
  51. Which of the following is a valid difference between embryonic stem cells and the stem cells found in adult tissues?
  52. A mutation in a single gene may cause a major change in the body of a fruit fly, such as an extra pair of legs or wings. Yet it probably takes the combined action of hundreds or thousands of genes to produce a wing or leg. How can a change in just one gene cause such a big change in the body?
  53. Genes can be cloned in recombinant plasmids.
    Gene cloning is one application of biotechnology, the manipulation of organisms or their components to make useful products. Researchers can create plasmids containing recombinant DNA and insert those plasmids into bacteria. If the recombinant bacteria multiply into a clone, the foreign genes are also duplicated and copies of genes or its protein product can be harvested.
  54. Enzymes are used to "cut and paste" DNA.
    Restriction enzymes cut DNA at specific sequences, forming restriction fragments. DNA ligase "pastes" DNA fragments together.
  55. Cloned genes can be stored in genomic libraries.
    Genomic libraries, sets of DNA fragments containing all of an organism's genes, can be constructed and stored using cloned bacterial plasmids, phages, or bacterial artificial chromosomes (BACs).
  56. Reverse transcriptase can help make genes for cloning.
    cDNA libraries contain only the genes that are transcribed by a particular type of cell.
  57. Nucleic acid probes identify clones carrying specific genes.
    A short, single-stranded molecule of labeled DNA or RNA can tag a desired gene in a library.
  58. Recombinant cells and organisms can mass-produce gene products.
    Bacteria, yeast, cell cultures, and whole animals can be used to make products for medical and other uses.
  59. DNA technology has changed the pharmaceutical industry and medicine.
    Researchers use gene cloning to produce hormones, diagnose disease, and produce vaccines.
  60. Genetically modified organisms are transforming agriculture.
    A number of important crop plants are genetically modified.
  61. Genetically modified organisms raise concerns about human and environmental health.
    Genetic engineering involves risks, such as ecological damage from GM crops.
  62. The analysis of genetic markers can produce a DNA profile.
    DNA technology- methods for studying and manipulating genetic material- has revolutionized the field of forensics. DNA profiling- the analysis of DNA fragment- can determine whether two samples of DNA come from the same individual.
  63. The PCR method is used to amplify DNA sequences.
    The polymerase chain reaction (PCR) can be used to amplify a DNA sample. The use of specific primers that flank the desired sequence ensures that only a particular subset of the DNA sample will be copied.
  64. STR analysis is commonly used for DNA profiling.
    Short tandem repeats (STRs) are stretches of DNA that contain short nucleotide sequences repeated many times in a row. DNA profiling by STR analysis involves amplifying a set of 13 STRs.
  65. DNA profiling has provided evidence in many forensic investigations.
    The applications of DNA profiling include helping to solve crimes and establishing paternity.
  66. RFLPs can be used to detect differences in DNA sequences.
    Restriction fragment length polymorophisms (RFLPs) reflect differences in the sequences of DNA samples.
  67. Genomics is the scientific study of whole genomes.
    Genomics researchers have sequenced many prokaryotic and eukaryotic genomes. Besides being of interest in their own right, nonhuman genomes can be compared with the human genome.
  68. The Human Genome Project revealed that most of the human genome does not consist of genes.
    Data from the Human Genome Project (HGP) revealed that the human genome contains about 21,000 genes and a huge amount of noncoding DNA, much of which consists of repetitive nucleotide sequences and transposable elements that can move about within the genome.
  69. The whole-genome shotgun method of sequencing a genome can provide a wealth of data quickly.
    The HGP uses genetic and physical mapping of chromosomes followed by DNA sequencing. Modern genomic analysis often uses the faster whole genome shotgun method.
  70. Molecular Biology
  71. Bacteriophages (phages)
  72. Nucleotides
  73. Polynucleotide
  74. Sugar-phosphate backbone
  75. DNA (deoxyribonucleic acid)
  76. Thymine
  77. Cytosine
  78. Adenine
  79. Guanine
  80. Uracil
  81. Double Helix
  82. Semiconservative Model
  83. DNA polymerase
  84. DNA ligase
  85. Transciption
  86. Translation
  87. Triplet Code
  88. Codons
  89. Genetic Code
  90. RNA polymerase
  91. Promoter
  92. Terminator
  93. Messenger RNA (mRNA)
  94. Introns
  95. Exons
  96. RNA splicing
  97. Transfer RNA (tRNA)
  98. Ribosomes
  99. Ribosomal RNA (rRNA)
  100. Start Codon
  101. Codon Recognition
  102. Peptide Bond Formation
  103. Translocation
  104. Stop Codon
  105. Mutation
  106. Silent Mutation
  107. Missense Mutation
  108. Nonsense Mutations
  109. Reading Frame
  110. Mutagenesis
  111. Mutagens
  112. Virus
  113. Capsid
  114. Lytic Cycle
  115. Lysogenic Cycle
  116. Prophage
  117. AIDS
  118. HIV
  119. Reverse Transcriptase
  120. Retrovirsuses
  121. Viroids
  122. Prions
  123. Transformation
  124. Transduction
  125. Conjugation
  126. Plasmid
  127. R Plasmids
  128. Gene Regulation
  129. Gene Expression
  130. Promoter
  131. Operator
  132. Operon
  133. Repressor
  134. Regulatory Gene
  135. Activators
  136. Differentiation
  137. Nucleosome
  138. Epigenetic Inheritance
  139. X Chromosome Inactivation
  140. Barr Body
  141. Transcription Factors
  142. Enhancers
  143. Alternative RNA Splicing
  144. microRNAs (miRNAs)
  145. RNA interference (RNAi)
  146. Homeotic Gene
  147. DNA microarray
  148. Signal Transduction Pathway
  149. Regeneration
  150. Clone
  151. Nuclear Transplantation
  152. Reproductive Cloning
  153. Embryonic Steam Cells (ES cells)
  154. Therapeutic Cloning
  155. Adult Stem Cells
  156. Oncogene
  157. Proto-oncogene
  158. Tumor-Suppressor Genes
  159. Carcinogens
  160. Biotechnology
  161. DNA Technology
  162. Recombinant DNA
  163. Genetic Engineering
  164. Gene Cloning
  165. Vector
  166. DNA ligase
  167. Restriction Enzymes
  168. Restriction Site
  169. Restriction Fragments
  170. Genomic Library
  171. Reverse Transcriptase
  172. Complementary DNA (cDNA)
  173. Nucleic Acide Probe
  174. Vaccine
  175. Genetically Modified Organisms (GM)
  176. Transgenic Organism
  177. Ti Plasmid
  178. Gene Therapy
  179. Forensics
  180. DNA Profiling
  181. Polymerase Chain Reaction (PCR)
  182. Primers
  183. Gel Electrophoresis
  184. Repetitive DNA
  185. Short Tandem Repeat (STR)
  186. STR Analysis
  187. Single Nucleotide Polymorphism (SNP)
  188. Restriction Fragment Length Polymorphism (RFLP)
  189. Genomics
  190. Human Genome Project (HGP)
  191. Telomeres
  192. Transposable Elements
  193. Whole-Genome Shotgun Method
  194. Proteomics