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What organisms are thought to be the first cells to appear on earth?

Archae

Which component is not found in the cytoplasm of the majority of procaryotes?

Capsule

What term refers to the fine, hairlike bristles that aid in adhesion in procaryotic organisms?

Fimbriae

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

What type of organisms possesses axial filaments?

Spirochetes

What type of appendage may be responsible for the formation of biofilms?

Fimbria

Pili, elongated tubular structures composed of pilin, are only found on what type of organisms?

Gram negatives

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

What is the key differentiating step in the Gram stain procedure?

Application of the mordant

The outermost layer of the outer membrane is composed of what?

Lipopolysaccharide

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?

Mycolic acid

What is not a function of the bacterial cytoplasmic membrane?

Storage of nutrient reserves

How many chromosomes do bacteria possess?

One

Which of the following is incorrect regarding plasmids?

They are essential for bacterial growth and survival

Under what conditions can endospores form?

When carbon and nitrogen sources become depleted

What is not one of the three general shapes possessed by bacteria?

Pleomorphic

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?

Quantitative analysis

Current strategies for determining evolutionary relatedness between organisms rely upon what?

rRNA sequence analysis

What type of bacteria naturally lacks a cell wall?

The Mycoplasmas

In spore formation, the stage in which DNA condenses and aligns itself in the center of the cell is called

mother cell

The spore layer containing peptidoglycan is the

cortex

As calcium enters the spore

water is removed from the cell

The protein coat forms outside the exosporangium.

False

Spore formation is initiated when there is a scarcity of nutrients and conditions are adverse.

True

How do bacteria communicate with each other?

Chemical molecules

What is this type of communication known as?

Quorum sensing

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.

cells

an individual membrane-bound living entity; the smallest unit capable of an independent existence

cytoplasm

dense fluid encased by the cell membrane; the site of many of the cell's biochemical and synthetic activities

chromosome

tightly coiled bodies in cells that are the primary sites of genes

ribosome

a bilobed macromolecular complex of ribomucleoprotein that coordinates the codons of mRNA with tRNA anticodons and, in doing so, constitutes the peptide assembly site

organelles

a small component of eurocaryotic cells that is bounded by a membrane and specialized in function

metabolism

a general term for the totality of chemical and physical processes occurring in a cell

irritability

capacity of cells to respond to chemical, mechanical, or light stimuli. this helps cells adapt to the environment and obtain nutrients

flagella

a srtucture that is used to propel the organism through a fluid environment

axial filaments

a type of flagellum (called an endoflagellum) that lies in periplasmic space of spirochetes and is responsible for locomotion; also called periplasmic flagellum

fimbriae

a short, numerous surface appendage on some bacteria that provides adhesion but not locomotion

pili

small, still filamentous appendages in gram-negative bacteria that function in DNA exchange during bacterial conjugation

glycocalyx

a filamentous network of carbohydrate-rich molecules that coat cells

peptidoglycan

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

gram stain

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

outer membrane

a structure made of lipids in the outer layer of the cell wall of a gram-negative bacteria

nucleoid

the basophilic nuclear region or nuclear body that contains the bacterial chromosome

plasmids

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

inclusions

a relatively inert body in the cytoplasm such as storage granules glucogen, fat, or some other aggregater metabolic product

cytoskeleton

a fine intracellular network of fibers, filaments, and other strands that function in support and shape of cells

bacterial actin

fine protein fibers within cells that contribute to structure and support

endospore

a small, dormant, resistant derivative of a bacterial cell that germinates under favorable growth conditions into a vegetative cell

cocci

a spherical-shaped bacterial cell

bacilli

bacterial shape that is cylindrical

spirilla

a type of bacterial cell with a rigid spiral shape and external flagella

spirochetes

a coiled, spiral-shaped bacterium that has endoflagella and flexes as it moves

pleomorphic

normal variability of cell shapes in a single species

coccobacilli

an elongated coccus; a short, thick oval-shaped bacterial rod

vibrios

a curved, rod-shaped bacterial cell

diplococci

spherical or oval shaped bacterial cells, typically found in pairs

tetrads

groups of four

sarcina

a cubical packet of 8, 16, or more cells

palisades

the characteristic arrangement of Corynebacterium (italics) cells resembling a row of fence posts and created by snapping

strains

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.

rickettsias

edically important family of bacterial, commonly carried by ticks, lice, and fleas. Significant cause of important emerging diseases

obligate

without alternative, restricted to a particular characteristic

Bacterial cells could have any of the following appendages except

cilia

The short, numerous appendages used by some bacterial cells for adhering to surfaces are called

fimbriae.

The transfer of genes during bacterial conjugation involves rigid, tubular appendages called

sex pili.

All bacterial cells have

a chromosome.

The term that refers to the presence of flagella all over the cell surface is

peritrichous.

The outcome of the Gram stain is based on differences in the cell's

cell wall.

A bacterial cell exhibiting chemotaxis probably has

flagella.

If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is

cell wall.

Peptidoglycan is a unique macromolecule found in bacterial

cell walls.

A procaryotic cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is

gram positive.

A bacterial genus that has waxy mycolic acid in the cell walls is

Mycobacterium.

Lipopolysaccharide is an important cell wall component of

gram negative bacteria.

The site/s for most ATP synthesis in procaryotic cells is/are the

cell membrane.

The bacterial chromosome

is part of the nucleoid.

The function of bacterial endospores is

protection of genetic material during harsh conditions.

Bacterial endospores are not produced by

Staphylococcus

When a rod shaped bacteria is short and plump, it is called a

coccobacillus

What is the correct sequence for a Gram stain?

crystal violet, Gram's iodine, alcohol, safranin

Bacteria with small bunches of flagella emerging from the same site are said to be

lophotrichous

Lysozyme, an enzyme found in tears, provides a natural defense against bacteria by

hydrolyzing peptidoglycan in cell walls.

In the Gram stain, the mordant is

iodine

Archaea do not have the typical peptidoglycan structure found in bacterial cell walls.

True

Bacteria in the genus Mycoplasma and bacteria called L-forms lack cell walls.

True

Gram negative bacteria do not have peptidoglycan in their cell walls.

False

The procaryotic cell membrane is a site for many enzymes and metabolic reactions.

True

The procaryotic cell membrane is a site for many enzymes and metabolic reactions.

True

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.

False

Endospores of certain bacterial species can enter tissues in the human body, germinate, and cause an infectious disease.

True

Iodine is the decolorizer in the Gram stain.

False

The _____ stain is used to stain and differentiate Mycobacterium and Nocardia from other bacteria.

Acid-fast

The procaryotic flagellum has three parts: the _____, the hook, and the basal body.

Filament

Movement of a cell toward a chemical stimulus is termed _____.

Chemotaxis

The cell _____ is composed of three layers: the glycocalyx, the cell wall, and the cell membrane.

Envelope

During the Gram stain, gram _____ cells decolorize when the alcohol is applied.

Negative

The enzyme _____, that is found in tears and saliva, can hydrolyze the bonds in the glycan chains of certain bacterial cell walls.

Lysozyme

Cells form a _____ arrangement when cells in a chain snap back upon each other forming a row of cells oriented side by side.

Palisade

_____ Manual of Systematic Bacteriology is a manual of bacterial descriptions and classifications.

Bergey's

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