117 Questions
Who invented the microscope and described the first microbes as the fruiting structures of fungi?
Antonie van Leeuwenhoek
Which scientist conducted the meat and flies experiment, leading to the disproval of the idea of spontaneous generation for large organisms?
Francesco Redi
Who failed to grow microbes in sterilized meat broth by boiling and not allowing air access?
Louis Pasteur
Which scientist used the Swan-necked flask experiment to disprove spontaneous generation?
Louis Pasteur
What was the main purpose of Francesco Redi's meat and flies experiment?
To disprove the idea of spontaneous generation for large organisms
What is the main characteristic of endosymbiotic organisms, like mitochondria?
They live inside of another organism
Which of the following is a characteristic of bacterial genomes?
They have little non-coding DNA
What is the function of the DNA control sequence in regulating gene expression?
Regulates transcription of structural genes
What is the main function of the nucleoid in bacterial cells?
Contains multiple loops of chromosomes
What are genes that have shared ancestry known as?
Homologs
Which process involves DNA uptake from the environment and can be induced by stress?
Transformation
What enhances the competence of bacteria cells for DNA transfer in Gram-negative bacteria?
$CaCl_2$ and low temperature
What is the fate of DNA entering a bacterial cell?
It undergoes recombination with the recipient's DNA
What are the specific recombination proteins required for site-specific recombination?
Recombinase enzymes
What type of transduction can transfer any gene from a donor to a recipient cell?
Generalized transduction
Which process involves cell-cell contact and is initiated by a pilus protruding from the donor cell?
Conjugation
What do bacterial colonies represent?
The progeny of one original cell
What did Angelina & Walther Hesse discover?
A solid medium using agar for bacterial culture growth
According to Robert Koch's Postulates, what is the first requirement to prove that a specific type of microorganism causes a specific disease?
The suspect organism should be present in all cases of disease & absent from healthy
What is the Miller-Urey Experiment aimed to simulate?
Chemical and energy conditions of prehistoric Earth's 'water cycle'
What is the function of a molecular clock in evolutionary biology?
To determine the genetic relatedness between species
What is the Shine-Dalgarno sequence responsible for?
Allowing binding of mRNA to ribosomes
Who discovered that prokaryotes lived in hot springs and produced methane?
Carl Woese
What is phylogenetics the study of?
Evolutionary relationships among biological individuals
What is a common characteristic of archaea and bacteria?
Similar size and shape
What is a limitation of Robert Koch's Postulates?
Slow growing pathogens/pathogens may fail postulate
What was the aim of the Miller-Urey Experiment?
To simulate chemical and energy conditions of prehistoric Earth's 'water cycle'
What are stromatolites?
Fossilized evidence of bacterial communities
Which enzyme recognizes and repairs bases that mostly do not distort DNA structure?
Methyl mismatch repair
What is the function of RecA in the SOS response?
Activates protease/self-break of LexA
What is the role of Rho in transcription termination?
Binds mRNA and moves along
Which factor is needed for the initiation of RNA synthesis and recognizes -10 & -35 promoters?
Sigma factor
What is the function of the Shine-Dalgarno sequence in translation?
Binds to 30s subunit
In bacterial cells, what does FtsZ form?
"Z-ring" in spherical cells
What is the function of MreB in bacterial cells?
"Coil inside rod-shaped cells"
What is the function of CreS in bacterial cells?
"Forms "Crescentin" along the inner side of crescent-shaped bacteria"
What is the role of Hapnoids in bacterial cell membrane?
Strengthening lipid membrane
What is the function of Sacculus in bacterial cells?
Rigid structure outside of phospholipid membrane
What distinguishes Gram-negative bacteria from Gram-positive bacteria in terms of cell wall structure?
Lipopolysaccharide (LPS) presence
What is the function of DNA helicase in bacterial DNA replication?
Unwinds the two strands of DNA
What is the role of DNA polymerase III in bacterial DNA replication?
Synthesizes new DNA strands
What is the function of RNA primers in bacterial DNA replication?
Produces RNA primers
What enzyme removes the RNA primers in bacterial DNA replication?
DNA polymerase I
In plasmid replication, what does it mean if a plasmid replicates only with the chromosome?
It is a stringent plasmid
What is the purpose of the ParMRC system in plasmids?
To maintain plasmids for self-maintenance
What is the Ames Test used for?
To test for mutagen strength
What is the main function of excision repair in DNA repair?
To remove damaged nucleotide(s)
What type of mutation changes the open-reading frame of a gene?
Frame-shift mutation
What enzyme binds to a pyrimidine dimer and cleaves the cyclobutane ring upon exposure to UV radiation?
Photolyase enzyme
What type of mutagen includes compounds that interfere with DNA chemistry, many of which are carcinogens?
Chemical mutagens
What type of mutation changes a purine to a pyrimidine, or vice versa?
Transversion
What is the function of the glycocalyx?
It forms a network of polysaccharides on the cell surface
What is the primary function of a capsule in bacterial cells?
To protect against pH, viral infection, and extracellular enzymes
What is the role of transporters in the movement of molecules across the membrane?
To allow diffusion of substrates across the membrane
In which type of transport does the movement occur against the gradient and require energy?
Primary active transport
What is the main source of energy for the phosphotransferase system (PTS) in sugar transport?
ATP hydrolysis
What is the function of the Sec System in bacterial cells?
Transport of unfolded proteins requiring ATP hydrolysis to move out
What is the function of S-layers in Archaea and many bacteria?
Layers of protein/glycoprotein that protect against pH, viral infection, extracellular enzymes.
What is the role of ABC Transporters (ATP-Binding Cassette) in cellular processes?
Substrate-specific proteins that escort specific substrates to transporters.
In which type of secretion system do proteins have a signal tag telling secretion machinery to move them out?
Sec System.
What is the primary role of group translocation (phosphotransferase system) in bacterial cells?
Sugar transport with modification by phosphorylation to maintain a gradient.
What is the primary characteristic of microorganisms as mentioned in the historical background of microbiology?
They are genetically and metabolically diverse
Who observed the first single-celled organisms (bacteria)?
Antonie van Leeuwenhoek
What experiment involved sterilized meat broth by boiling, which led to the failure of microbial growth?
The Lazzaro Spallanzani experiment
What theory did Francesco Redi's meat/flies experiment disprove?
Spontaneous generation for large organisms
Who invented the microscope and described the first microbes as the fruiting structures of fungi?
Robert Hooke
What is the term for the theory that living creatures could arise without parents?
Spontaneous Generation
What did Louis Pasteur disprove with the Swan-necked flask experiment?
Spontaneous generation of microorganisms
What is the main purpose of Koch's Postulates?
To prove that a specific bacterium causes a specific disease
What is the main limitation of Koch's Postulates?
Slow-growing pathogens may fail the postulate
What is the Metabolist Model primarily about?
Formation of cellular metabolism from abiotic chemical reactions
What is the function of RNA in some viruses?
Has catalytic activity and synthesizes proteins in ribosomes
What is the main purpose of a molecular clock or evolutionary chronometer?
To measure a species' genome mutation rate and genetic relatedness
What does the Shine-Dalgarno sequence allow in mRNA?
Allows binding to the 30s subunit in bacterial cells
What did Carl Woese discover through his analysis of 16S rRNA?
Distinct form of life in hot springs producing methane
What is the focus of phylogenetics?
Study of evolutionary relationships among biological individuals
During bacterial DNA replication, which enzyme is responsible for unwinding the two strands of DNA?
DNA helicase
What is the term for the process where a DNA molecule replicates in a semi-conservative manner?
Semiconservative replication
Which enzyme synthesizes new DNA strands during bacterial DNA replication?
DNA polymerase III
What is the enzyme that removes the RNA primers during the completion of DNA replication?
DNA polymerase I
Which mutation type involves a change in a single base in the DNA sequence?
Transition
What is the main purpose of the Ames Test?
Identify mutagens in bacterial cells
Which structure is a protective and stabilizing layer made up of about 200 sugars?
O-specific polysaccharide
What is the main function of the proofreading mechanism during DNA replication?
Detect and correct mismatches in the DNA sequence
Which type of transport involves moving molecules from an area of low concentration to an area of high concentration, requiring energy?
Active transport
Which enzyme is responsible for cleaving the cyclobutane ring of a pyrimidine dimer upon exposure to UV radiation?
Photolyase
Which protein complex is used for the injection of toxins and harmful molecules into eukaryotic or bacterial cells?
Type VI secretion system
What type of mutagen includes compounds that change a base's structure and pairing characteristics?
Chemical mutagen
What is the primary energy source used in the phosphotransferase system (PTS) for sugar transport?
Phosphoenolpyruvate (PEP)
During bacterial DNA replication, what role do Single-stranded DNA binding proteins (SSBs) play?
Keep the single DNA strands apart during DNA synthesis
Which system is responsible for the transport of unfolded proteins requiring ATP hydrolysis to move out of the cell?
Sec System
What is the term used for the rapid accumulation of mutations due to exposure to mutagens or other factors?
Hypermutation phenotype
What is the function of S-layers in Archaea and many bacteria?
Protection against pH
Which type of transport involves movement of substances along a chemical gradient with no energy input required?
Facilitated diffusion
What process involves enzymatic cleavage of alien DNA by restriction endonucleases at specific sites?
DNA restriction and modification
Which statement is true about the diversity of microbial life?
Archaea and bacteria share similar ribosomes and metabolic pathways
What is the primary characteristic of endosymbiotic organisms like mitochondria?
They have their own circular genomes and prokaryotic-like ribosomes
What is the fate of most foreign DNA entering a bacterial cell?
It degrades by restriction endonucleases in the recipient cell
What process involves DNA uptake from the environment and can be induced by stress?
Transformation
What is the function of operons in bacteria?
To regulate expression of structural genes through DNA control sequences
What is the primary role of a pilus in bacterial cells?
To transfer DNA from one bacterium to another after cell-to-cell contact
What distinguishes Gram-negative bacteria from Gram-positive bacteria in terms of DNA replication?
Gram-negative bacteria replicate their circular chromosomes differently
What is the function of genomic islands in bacterial genomes?
To produce metabolites for the bacterial cell
What type of gene transfer involves cell-cell contact and is initiated by a pilus protruding from the donor cell?
Conjugation
What is the primary function of horizontal gene transfer in bacteria?
To acquire new genes from the environment through transformation
What is the main role of genomic islands in bacterial genomes?
To encode harmful genes that cause disease
What enhances the competence of bacteria cells for DNA transfer in Gram-negative bacteria?
The physiological state of the cell during early log phase growth
Which repair mechanism recognizes damage that causes distortion in DNA structure and involves an endonuclease removing a patch of single-stranded DNA containing damaged bases?
Nucleotide excision repair
What is the role of RecA in the SOS response?
Activates protease to break down LexA
Which enzyme is responsible for synthesizing RNA by adding complementary bases to the template strand?
RNA polymerase
What is the primary function of the bacterial cell wall?
Providing structural support and withstanding turgor pressure
What distinguishes Gram-negative bacteria from Gram-positive bacteria in terms of cell wall structure?
Absence of an outer membrane
What is the main function of FtsZ in bacterial cells?
Forming a structural ring in spherical cells
What molecule strengthens the lipid membrane in bacterial cells?
Hapanoids
Which transcription termination pathway involves the formation of a GC stem loop and subsequent destabilization at the poly-U site?
Rho-independent pathway
Which molecule serves as a ribosome-binding site on mRNA, allowing binding to the 30s subunit during translation?
Shine-Dalgarno sequence
Which enzyme removes damaged nucleotide(s) during excision repair mechanisms?
Endonuclease
Test your knowledge on the process of bacterial DNA replication, including the roles of replisome complexes, DNA helicase, single-stranded DNA binding proteins, clamp loader, sliding clamps, and DNA polymerase III.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
