What term refers to the fine, hairlike bristles that aid in adhesion in procaryotic organisms?
In a peritrichous arrangement of flagella, how are the flagella distributed over the organism?
Multiple flagella randomly dispersed over the cell surface
Why is the flagellum effective in guiding bacteria through the environment?
The system for chemical detection is linked to the mechanisms that drive the flagellum
In motile bacteria the presence of attractant molecules causes an increase in what?
The length of runs
Pili, elongated tubular structures composed of pilin, are only found on what type of organisms?
Which of the following is not an example of a biofilm?
A single bacterial cell growing on an agar surface
Why are encapsulated bacteria generally more pathogenic than unencapsulated strains?
Because the capsule helps prevent phagocyte attachment to the organism
Which of the following is incorrect regarding the bacterial cell wall?
It is composed of a repeating framework of lipids
Which statement describes why Gram negative organisms are more sensitive to lysis than Gram positive organisms?
The peptidoglycan layer of the cell while is quite thin
The acid fast stain is used to identify organisms containing what chemical in their cell walls?
Which of the following is incorrect regarding plasmids?
They are essential for bacterial growth and survival
The style of bacterial grouping, or arrangement, is based on what factor?
The number of planes in which the bacteria divide
Identification of bacteria requires a study of all but which of the following?
Current strategies for determining evolutionary relatedness between organisms rely upon what?
rRNA sequence analysis
In spore formation, the stage in which DNA condenses and aligns itself in the center of the cell is called
When are the genes turned on for chemical expression?
When their population number reaches a critical count
One of the interesting findings about bacteria communication is that
they seem to have a universal language between all bacterial species.
How is using bacterial communication knowledge as a proposed antibiotic method intended to work?
The antibiotic would stop the gene expression or detection of chemical signals.
an individual membrane-bound living entity; the smallest unit capable of an independent existence
dense fluid encased by the cell membrane; the site of many of the cell's biochemical and synthetic activities
a bilobed macromolecular complex of ribomucleoprotein that coordinates the codons of mRNA with tRNA anticodons and, in doing so, constitutes the peptide assembly site
a small component of eurocaryotic cells that is bounded by a membrane and specialized in function
capacity of cells to respond to chemical, mechanical, or light stimuli. this helps cells adapt to the environment and obtain nutrients
a type of flagellum (called an endoflagellum) that lies in periplasmic space of spirochetes and is responsible for locomotion; also called periplasmic flagellum
a short, numerous surface appendage on some bacteria that provides adhesion but not locomotion
small, still filamentous appendages in gram-negative bacteria that function in DNA exchange during bacterial conjugation
a network of polysaccharide chains cross-linked by short peptides that form the rigid part of bacterial cell walls. gram-negative bacteria have a small amount of this rigid structure than do gram-positive bacteria
a different stain for bacteria useful in identification and taxonomy. Gram-positive organisms appear purple from crystal violet-mordant retention, whereas gram-negative organisms appear red after loss of crystal violet and absorbance of the safranin couterstain
a structure made of lipids in the outer layer of the cell wall of a gram-negative bacteria
extrachromosomal genetic units characterized by several features. A plasmid is a double-stranded DNA that is smaller than and replicated independently of the cell chromosome; it bears genes that are not essential for cell growth; it can bear the genes that code for adaptive traits; and it is transmissible to other bacteria
a relatively inert body in the cytoplasm such as storage granules glucogen, fat, or some other aggregater metabolic product
a fine intracellular network of fibers, filaments, and other strands that function in support and shape of cells
a small, dormant, resistant derivative of a bacterial cell that germinates under favorable growth conditions into a vegetative cell
the characteristic arrangement of Corynebacterium (italics) cells resembling a row of fence posts and created by snapping
in microbiology, a set of descendents cloned from a common ancestor that retains the original characteristics. Any deviation from the original is a different strain.
edically important family of bacterial, commonly carried by ticks, lice, and fleas. Significant cause of important emerging diseases
The short, numerous appendages used by some bacterial cells for adhering to surfaces are called
The transfer of genes during bacterial conjugation involves rigid, tubular appendages called
If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is
A procaryotic cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is
Lysozyme, an enzyme found in tears, provides a natural defense against bacteria by
hydrolyzing peptidoglycan in cell walls.
If during the gram stain procedure, the bacterial cells were viewed immediately after crystal violet was applied, gram positive cells would be purple but gram negative cells would be colorless.
Endospores of certain bacterial species can enter tissues in the human body, germinate, and cause an infectious disease.
The _____ stain is used to stain and differentiate Mycobacterium and Nocardia from other bacteria.
The cell _____ is composed of three layers: the glycocalyx, the cell wall, and the cell membrane.
The enzyme _____, that is found in tears and saliva, can hydrolyze the bonds in the glycan chains of certain bacterial cell walls.
Cells form a _____ arrangement when cells in a chain snap back upon each other forming a row of cells oriented side by side.