QUESTIONS AND ANSWERS SURE A+
✔✔Inducible genes - ✔✔Default OFF; turned ON by inducer; catabolic pathways
✔✔Repressible genes - ✔✔Default ON; turned OFF by repressor; biosynthetic
pathways
✔✔Negative control - ✔✔Repressor blocks RNA polymerase
✔✔Positive control - ✔✔Activator enhances RNA polymerase binding
✔✔Lac operon structure - ✔✔lacI, CAP site, operator, lacZ lacY lacA; polycistronic
mRNA
✔✔Lac operon no lactose - ✔✔LacI binds operator; transcription blocked
✔✔Lac operon with lactose - ✔✔Allolactose binds LacI; repressor removed;
transcription occurs
✔✔Allolactose - ✔✔Inducer of lac operon; inhibits LacI
✔✔CAP and cAMP - ✔✔cAMP binds CAP; activates transcription when glucose is low
✔✔Diauxic growth - ✔✔Glucose used first; then lactose
✔✔Coupled transcription/translation - ✔✔Occurs simultaneously; allows rapid response
✔✔Quorum sensing - ✔✔Cell-density dependent gene regulation
✔✔Autoinducer - ✔✔Signaling molecule that accumulates with cell density
✔✔Vibrio fischeri - ✔✔Uses quorum sensing for bioluminescence
✔✔Mutation - ✔✔Heritable change in DNA
✔✔Spontaneous mutation - ✔✔Natural replication error
✔✔Induced mutation - ✔✔Caused by environmental factors
✔✔Point mutation - ✔✔Single base change
✔✔Insertion/deletion - ✔✔Adds or removes nucleotides
, ✔✔Silent mutation - ✔✔No change in protein
✔✔Missense mutation - ✔✔Different amino acid
✔✔Nonsense mutation - ✔✔Creates stop codon
✔✔Frameshift mutation - ✔✔Shifts reading frame; major effect
✔✔Vertical gene transfer - ✔✔Parent to offspring
✔✔Horizontal gene transfer - ✔✔Between organisms
✔✔Transformation - ✔✔Uptake of naked DNA
✔✔Transduction - ✔✔DNA transfer via bacteriophage
✔✔Conjugation - ✔✔DNA transfer via direct contact
✔✔Insertion sequence - ✔✔Simple transposable element
✔✔Transposon - ✔✔Mobile DNA with additional genes
✔✔Simple transposition - ✔✔Cut and paste
✔✔Replicative transposition - ✔✔Copy and paste
✔✔F+ cell - ✔✔Has F plasmid
✔✔F- cell - ✔✔Lacks F plasmid
✔✔F+ x F- result - ✔✔Both cells become F+
✔✔Hfr cell - ✔✔F plasmid integrated into chromosome
✔✔F' cell - ✔✔F plasmid carries chromosomal DNA
✔✔Generalized transduction - ✔✔Any gene transferred
✔✔Specialized transduction - ✔✔Specific genes transferred
✔✔Virus definition - ✔✔Obligate intracellular particle with genetic material + protein
coat