Bio/Biochem · 1B

Genes and gene expression

Content category 1B. 32 questions in 6 sets, each with reasoning for every answer choice.

Set 1 · Biotechnology

  1. PCR steps: denaturation, annealing, extensioneasy
  2. Northern vs. Southern vs. Western bloteasy
  3. Plasmid antibiotic resistance as a selectable markereasy
  4. Why use cDNA to express a human gene in bacteria?medium
  5. Restriction enzymesmedium

Set 2 · Biotechnology

  1. DNA in agarose gel electrophoresismedium
  2. Sanger sequencingmedium
  3. PCR amplification after 10 cycleshard
  4. Nucleotide excision repair of thymine dimersmedium
  5. DNA ligase and Okazaki fragmentseasy

Set 3 · DNA replication

  1. DNA replication vs. transcriptionmedium
  2. Meselson–Stahl: semiconservative replicationmedium
  3. Telomerase as a reverse transcriptasemedium
  4. DNA polymerase proofreading: 3′→5′ exonucleasemedium
  5. Nonsense vs. missense vs. silent mutationseasy

Set 4 · Gene expression

  1. Eukaryotic mRNA processing: the 5′ capeasy
  2. Alternative splicingeasy
  3. RNA polymerases I, II, and IIIeasy
  4. Wobble hypothesis and codon degeneracymedium
  5. Splice-site mutationsmedium

Set 5 · Gene regulation

  1. Lac operon: when is expression highest?medium
  2. Trp operon: repressible vs. induciblemedium
  3. Histone acetylation and transcriptionmedium
  4. DNA methylation and gene silencingmedium
  5. RNA interferencemedium

Set 6 · Gene regulation

  1. A lacI mutantmedium
  2. A lac operator mutation in a partial diploidhard
  3. How enhancers workhard
  4. Which mutation most likely abolishes protein function?medium
  5. Peptidyl transferase: the ribosome as a ribozymemedium
  6. The Shine–Dalgarno sequencemedium
  7. Energy cost of adding one amino acidhard