Bacterial Structure and Growth
This DNA-containing region of a bacterium is haploid, lacks a membrane, and carries all essential genetic information
What is the nucleoid?
The capsid plus its enclosed viral nucleic acid is known by this term
What is the nucleocapsid?
This medium contains bile salts to suppress Gram-positives and distinguishes lactose fermenters by colony color
What is McConkey agar?
This process involves uptake of naked DNA by a competent bacterial cell
What is transformation?
This key membrane sterol, targeted by many antifungal drugs, replaces cholesterol in fungal cell membranes
What is ergosterol?
This part of the Gram-negative cell wall is made of Lipid A, a core polysaccharide, and an O-antigen side chain
What is lipopolysaccharide (LPS)?
Viruses with a (–) single-stranded RNA genome must carry this enzyme to first make a (+) RNA template for mRNA synthesis
What is RNA-dependent RNA polymerase (replicase)?
A hydrogen peroxide test that produces bubbles indicates the presence of this enzyme, helping differentiate Staphylococcus (positive) from Streptococcus (negative).
What is the catalase test?
Dimorphic fungi such as Histoplasma grow as molds in the environment but switch to this form inside human tissue
What is the yeast form?
Bacteria within a community can sense population density and coordinate gene expression, such as bioluminescence or virulence factor production, through this process
What is quorum sensing?
Unlike enveloped viruses, most non-enveloped viruses exit the host cell by one of these two destructive processes
What is cell lysis?
This is the most common form of human prion disease, with an incidence of about 1 case per million per year and no known environmental trigger
What is sporadic Creutzfeldt–Jakob disease?
After plasmid conjugation, both bacterial cells now carry this structure
These asexual reproductive structures include arthrospores, chlamydospores, sporangiospores, conidiospores, and blastospores, and are crucial for fungal propagation and diagnosis
What are asexual spores?
Unlike obligate anaerobes, these organisms can’t use oxygen to grow but tolerate its presence without harm; they are obligate fermenters
What are aerotolerant bacteria?
Retroviruses differ from other (+) RNA viruses because they reverse transcribe their genome into this molecule before integrating into the host genome.
What is complementary DNA (cDNA)?
Unlike NAATs, this method uses fluorescent probes to bind directly to 16S rRNA in whole cells and does not require prior DNA amplification
What is fluorescence in situ hybridization (FISH)?
Conjugation is a major driver for spreading genes that give bacteria this medically critical trait
What is antibiotic resistance?
Filamentous fungi grow as thread-like structures called hyphae that form a visible network called this
What is a mycelium?
This reagent is applied after acid-alcohol and stains non–acid-fast cells blue, providing contrast to the red acid-fast cells
What is methylene blue?
This laboratory method can directly visualize viral particles and even discover new ones, but requires a high viral load and special equipment
What is electron microscopy?
This practical approach groups bacteria by visible traits like shape and growth, but fails to represent evolutionary relatedness
What is phenotypic classification?
In a parasite’s life cycle, this type of host harbors the adult or sexually mature stage of the parasite, whereas an intermediate host contains an immature or asexual stage
What is a definitive host?
Direct microscopic examination of clinical specimens often uses 10% KOH, but this special stain colors fungal walls black and is frequently used to detect hyphae and spores
What is Gomori methenamine silver (GMS) stain?