Skip to main content
Back

Microbial Genetics - Microbiology

Control buttons has been changed to "navigation" mode.
1/21
  • What is genetics?

    Genetics is the study of genes, how they carry information, how information is expressed, and how genes are replicated.

  • Define genotype and phenotype.

    Genotype is the genetic makeup of an organism, while phenotype is the expression of the genes.

  • What is the central dogma of molecular biology?

    DNA is transcribed into mRNA, which is then translated into protein, resulting in gene expression.

  • Describe the structure of bacterial chromosomes.

    Bacteria usually have a single circular chromosome made of DNA and associated proteins, often supercoiled.

  • What is vertical gene transfer?

    Vertical gene transfer is the flow of genetic information from one generation to the next.

  • What are the key enzymes involved in DNA replication?

    Topoisomerase and gyrase relax strands, helicase separates strands, and DNA polymerase synthesizes new DNA strands.

  • How is the lagging strand synthesized during DNA replication?

    Discontinuously, creating Okazaki fragments that are later joined by DNA polymerase and DNA ligase.

  • What are the three main types of RNA in protein synthesis?

    Ribosomal RNA (rRNA), transfer RNA (tRNA), and messenger RNA (mRNA).

  • What is transcription in prokaryotes?

    Transcription is the synthesis of a complementary mRNA strand from a DNA template by RNA polymerase.

  • What is the role of codons in translation?

    Codons are groups of three mRNA nucleotides that code for specific amino acids during protein synthesis.

  • What is an inducible operon?

    An operon that is normally off but can be turned on by an inducer, e.g., the lac operon in E. coli.

  • How does a repressible operon function?

    It is normally on but can be turned off by a corepressor activating the repressor, e.g., the trp operon.

  • Define mutation.

    A permanent change in the base sequence of DNA that may be neutral, beneficial, or harmful.

  • What is a frameshift mutation?

    Insertion or deletion of nucleotides that shifts the reading frame, altering many downstream amino acids.

  • What types of radiation cause mutations?

    Ionizing radiation (X-rays, gamma rays) and UV radiation, which causes thymine dimers.

  • How do bacteria repair UV-induced DNA damage?

    Using photolyases (light repair) and nucleotide excision repair enzymes.

  • What is horizontal gene transfer?

    Transfer of genes between cells of the same generation, involving donor and recipient cells.

  • What are plasmids?

    Self-replicating circular DNA molecules in bacteria that may carry genes for antibiotic resistance or pathogenicity.

  • Describe bacterial conjugation.

    Transfer of plasmids between bacteria via direct cell-to-cell contact, often using sex pili in Gram-negative bacteria.

  • What is transformation in bacteria?

    Uptake of naked DNA from the environment by a bacterial cell.

  • What is transduction in bacteria?

    Transfer of bacterial DNA from donor to recipient via a bacteriophage.