L10-12 quiz

• segment polarity genes divide the Drosophila embryo into 14 repeating units
• RNA polymerase bind to a site on DNA called the _ before initiating transcription 


  promoter
• the initial course of Drosophila development is determined by

  maternal genes
• maternal genes are expressed by the female during oogenesis, which code for mRNA (stored in the egg until fertilisation when they are translated and program early development)
• shapes in DNA binding sites examples:

  • zinc finger
  • homeodomain
  • leucine zipper
• eukaryotic DNA:

  • exceeding long and fragile molecule
  • packaged into successively compact formations
  • when in condensed form, is transcriptionally inactive
  • must be unpackaged before it can be transcribed into RNA
  • contains regions which do not code for proteins, some are introns, some are non-coding DNA between genes
• determination is the commitment of a particular cell to a specialized developmental path
• differentiation is where the cell expresses its characteristic set of proteins
• introns are not found in mature mRNA and therefore do not code for protein
• not all non-coding DNA is found in introns
• the integration of a bacteriophage into a bacterial genome is called

  lysogeny
• integrated genome is called a prophage and the bacterium carrying the prophage is called a lysogen
• regulatory proteins shut off transcription by binding to an operator site immediately in front of the promoter and often overlapping it
• the operator is the binding site for a repressor protein which prevents transcription by blocking the promoter
• transcriptional control is the most common form of regulation in bacteria and eukaryotes
• transcriptional control is most common regulation of gene expression because:


  more energy-efficient