Microbiology

The canning food industry must be sure their process destroys which of the following bacteria that can cause food poisoning?

botulinum

------ ------- in endospores removes water and leaves the endospore very dehydrated.

calcium dipicolinate

Which of the following prevents the rupture of bacterial cells by internal osmotic pressure?

cell wall

----------- diphtheriae are generally rod-shaped, in culture they may club-shaped, swollen, curved, filamentous and coccoid variations.

corynebacterium

Which of the following are functions of the bacterial cell membrane?

A barrier between the internal and external contents of the cell Provide a site for nutrient processing and synthesis Provide a site for energy reactions

The cell membranes of archaea contain which of the following?

Branched hydrocarbons

What cell envelope component is not a static structure?

Cell membrane

Pili are typically used for which of the following? a)Structural b)Protection c)Conjugation d)Motility

Conjugation

The transfer of DNA between bacterial cells is called ---------

Conjugation

Which of the following has internal membranes that are the site of photosynthesis?

Cyanobacteria

The main function of the external appendages known as ----------- is to stick to other cells and surfaces, which may lead to aggregates known as biofilms and colonization of microbes on inanimate objects.

Fimbriae

When conditions are favorable, bacterial endospores break dormancy, known as entering which of the following cycles?

Germination

Which type of cell wall is thinner and does not retain the crystal violet stain in the gram stain?

Gram negative

Endotoxin is toxic to which of the following cells?

Human and other mammalian cells

Bacteria often store excess nutrients in membrane bound compartments called which of the following?

Inclusions

Which causes primary atypical "walking" pneumonia?

Mycoplasma

The bulk of the Gram-positive cell wall is a homogeneous sheath of which of the following?

Peptidoglycan

identify the area between the cell wall and cell membrane in gram-positive bacteria.

Periplasmic space

Which of the following are small, circular pieces of DNA that exist independently within bacterial cytoplasm?

Plasmids

Which term specifically describes the cubical arrangement of 4 cocci?

Tetrad

The --------- is an extracellular material that is closely associated with biofilm formation.

glycocalyx

Cytoplasmic -------, such as granules or vesicles, can store organic and inorganic nutrients and even gases or magnetic iron oxides.

inclusions

Which of the following occurs when a cell breaks or ruptures?

lysis

The cell envelope of gram---------bacteria is composed of an outer membrane, cell wall, and a cell membrane.

negative

In prokaryotes, the chromosomal DNA is aggregated in a central area called the

nucleoid

How many chromosomes do most bacteria contain?

one

The cell wall in bacteria is primarily composed of

peptidoglycan or PPG, OR PG

The ------------ below the peptidoglycan layer of gram-negative bacteria is the site of many metabolic reactions related to the synthesis and transport of proteins.

periplasmic

Identify the major structure component of the cell membrane.

phospholid

Bacterial pili are composed of the protein ----------

pilin

The small, circular pieces of DNA of bacterial cells which can carry the traits for antibiotic resistance or toxin production are called -----

plasmids

Which of the following are small, circular pieces of DNA that exist independently within bacterial cytoplasm?

plasmids

In the fluid mosaic model, the membrane is a continuous bilayer formed by lipids with the ________ oriented outward and the ________ towards the center.

polar heads, nonpolar tails

The Gram--------- cell wall contains peptidoglycan, teichoic acid, and

positive

Fungal spores function in _______, while bacterial spores function in _______.

production, protection

What are porins?

protein channels that span the outer membrane

According to the fluid mosaic model, the lipid bilayer is embedded with numerous globular ----------

proteins

----------------is a behavior of biofilms which occurs when individual species alter the expression of their genes to cooperate with other cells in the biofilm.

quorum sensing

Gram-negative cells that have lost their cell wall are specifically called

spheroplasts

Fungal spores function in both survival and reproduction, while bacterial endospores function in survival only.

true

True or false: Bacterial endospores are more resistant to disinfectants than vegetative cells.

true

he metabolically active and growing phase of endospore forming bacteria is called the

vegetative cell

Peptidoglycan in the cell -------- provides the structural support necessary to protect bacteria from lysis due to internal pressure.

wall

Mycolic acid is also called the ------ FACTOR

CORD

The presence of mycolic acid in which of the following genera of bacteria contributes to the pathogenicity of these organisms?

Mycobacterium Nocardia

Which of the following is part of the cell wall of mycobacteria?

Mycolic acid Peptidoglycan

Which bacteria have no cell wall, but have a cytoplasmic membrane that is stabilized by sterols?

Mycoplasma

Neisseria gonorrhoeae binds to the epithelial cells of the reproductive tract by means of which of the following? a)Fimbriae b)F pilus c)Type IV pili d)Peritrichous flagella

Type IV pili

Endotoxins (LPS) can stimulate fever and shock during which gram-negative infections?

Typhoid fever Meningitis

Which of the following describes the periplasmic space in gram-negative bacteria?

Well-developed

What cell envelope component is not a static structure?

cell membrane

Which is the dormant survival state in endospore-forming bacteria?

endospore

The cell membrane consists of a(n) ------- bilayer with embedded --------

phospholipid or lipid, protein, proteins, globular proteins, or membrane proteins

Which structure has a small and large subunit and is composed of rRNA and protein?

ribosome

The genus Bacillus contains bacteria of which shape?

rod

The -------- ----------- is a protective covering in some bacteria. It is composed of thousands of copies of a single protein.

s layer

A palisades arrangement of cells is typical in which of the following bacteria?

Corynebacteria

What is the difference between a true nucleus and a nucleoid?

A true nucleus is surrounded by a membrane whereas a nucleoid is not.

The -------- ---------stain is useful in the diagnosis of tuberculosis and leprosy.

AF (acid fast) or Ziehl Neelsen

Which of the following is the major factor that stimulates endospore formation?

Depletion of nutrients

When a bacterial cell loses its cell wall, it is known as which of the following?

L form

Tears and saliva contain ---------, an enzyme which digests peptidoglycans and breaks down bacterial cell walls.

LYSOZYME

Which of the following bacteria could exhibit phototaxis? a)Staphylococcus aureus B)Helicobacter pylori C)Escherichia coli D)Photosynthetic bacteria

Photosynthetic bacteria

Which of the following describes movement towards or away from light ? 1) Phototaxis 2)Chemotaxis

Phototaxis

Place the steps of endospore formation into the correct order (from stimulus to mature endospore).

1) DNA replication. place the steps of endospore formation into the correct order (from stimulus to mature endospore) 2) septation of cell. ... 3) sporangium engulfs forespore. ... 4) synthesis of spore layers. ... 5) Deposition of cortex and outer coat layers. ... 6) Mature endopore formed.

Identify three advantages of endospore formation.

1)The endospore provides protection in dry conditions. 2)The endospore is more resistant to antimicrobial agents. 3)Endospores are highly resistant to radiation and heat.

Endospore formation in spore-forming bacteria takes about how much time?

6-12 hrs

What is the glycocalyx? a)An intracellular substance that confers antibiotic resistance to the cell b)An enzyme present in the periplasmic space c)The major component of the bacterial cell wall d)An extracellular coating that provides protection to the cell

An extracellular coating that provides protection to the cell

Which of the following bored through the stomach lining and causes gastric ulcers? a) Klebsiella pneumoniae B) Streptococcus pneumoniae c) Proteus vulgaris d) Helicobacter pylori

Helicobacter pylori

L forms of bacteria can be formed artificially by which of the following chemically treatments?

Lysozyme Penicillin

All bacteria possess a cell ----------but not all bacteria possess a cell-----------

MEMBRANE, WALL

identify which of the following are external structures used primarily for direct contact interactions with other cells a ) Flagella b) Fimbriae c) Cilia d) Pili

PILI, Fimbriae

Gram-positive cells that have lost their cell wall are called

PROTOPLASTS

Which of the following antibiotics affect the integrity of the cell wall of bacteria, thereby making them susceptible to lysis?

Penicillin Cephalosporin

Which of the following describes a rigid, loosely twisted, helical bacterium?

Spirillum

A tightly-coiled, yet flexible helical bacterium is described as which of the following?

Spirochete

Which of the following are rigid lipids that stabilize the cell membranes of mycoplasmas?

Sterols

Which phrase means that a cell can have various shapes?

Pleomorphic

Identify the term for multiple shapes and sizes among cells of the same species

Pleomorphism

Which of the following are gram-positive cells that have lost their cells walls, usually as a result of the activity of lysozyme or penicillin?

Protoplasts

Which of the following are functions of the bacterial cell membrane?

Provide a site for energy reactions Provide a site for nutrient processing and synthesis A barrier between the internal and external contents of the cell

The presence of type IV pili cause a type of twitching movement in bacteria of which of the following genera? a)Pseudomonas b)Escherichia c)Yersinia d)Staphylococcus

Pseudomonas

Which cellular structure is responsible for synthesizing proteins?

Ribosome

Which is the term for a cubical packet of 8, 16, or more cells?

Sarcina

What structural difference is found in gram-positive cells but not in gram-negative cells?

Single cell membrane

Which structure is most closely associated with biofilm formation? a)Slime layer b)Cell membrane c)Endospores

Slime layer

Which type of glycocalyx is loosely attached to the bacterial cell and protects it from dehydration and loss of nutrients?

Slime layer

The cytoskeleton is an intracellular network of -------- ------------and intermediate filaments that are found throughout the cytoplasm of eukaryotic cells and contribute to cell shape.

actin or microfilament; tubulin or microtubule

Peptidoglycan is a component of the cell wail of which of the following organisms?

bacteria

The --------- is the name given to a structure external to and bound tightly to the cell wall that is made of polysaccharides and proteins and contributes to the pathogenicity of the organism.

capsule

Which of the following structures is external and can protect the bacterial cell from various host immune responses?

capsule

Which of the following acts as a selective barrier between the internal and external contents of the cell?

cell membrane

Identify the two main components of the cell envelope in most bacteria.

cell wall, cell mebrane

The hereditary material of most bacteria exists in the form of a single

circular

when a rod-shaped bacterium is short and plump it is called a(n) ------ and if it is gently curved it is called a(n) -----------

coccobacillus , vibrio

The cell envelope encloses the -----

cytoplasm

The cell membrane surrounds a complex solution of organic materials and salts that is referred to as

cytoplasm

Recent evidence suggests that bacteria, like eukaryotic cells, maintain and support cell shape through a network of protein fibers called which of the following?

cytoskeleton

lipopolysaccharide (LPS) is classified as is a(n)

endotoxin

Bacteria are able to attach to surfaces and other bacteria using the surface appendages known as --------- and ---------------.

fimbriae. pili

The is a polysaccharide protective coating outside of the bacterial cell wall that is called either a capsule or slime layer based on its structure.

glycocalyx

The depletion of nutrients, especially amino acids, is a stimulus for -------- in bacteria

sporulation

------------diphtheriae and -------------pyogenes are gram-positive bacteria that have toxic properties due to proteins on their cell walls.

CORYNEBACTERIUM STREPTOCOCCUS

Select all that apply Identify the two types of glycocalyx in bacteria. a)Capsules b)Outer membrane c)Peptidoglycan d)Slime layer e)Lipopolysaccharide

Capsules, Slime layer

the function of teichoic acid and lipoteichoic acid in the Gram-positive cell wall includes which of the following? a)Response to external stimuli b)Cell wall maintenance c)Attachment to to other cells for DNA exchange d)Cell wall enlargement

Cell wall maintenance Cell wall enlargement

Identify the spore-forming bacterium that causes botulism.

Clostridium botulinum

Which of the following bacteria can produce an S layer under harsh conditions?

Clostridium difficile Bacillus anthracis

What is a spherically-shaped bacterial cell termed?

Coccus

Elongated, rigid tubes on gram-negative bacteria that are involved in the transfer of DNA from one cell to another are called which of the following? a)Slime layers b)Conjugation pili c)Sex fimbriae d)Axial filaments

Conjugation pili

Which of the following is the intracellular gelatinous solution?

Cytoplasm

Recent evidence suggests that bacteria, like eukaryotic cells, maintain and support cell shape through a network of protein fibers called which of the following?

Cytoskeleton

Which of the following is formed during bacterial sporulation?

Endospore

Which of the following bacteria use their flagella to invade mucus membranes and cause infections? a)Vibrio cholerae b)Streptococcus pneumoniae c)Helicobacter pylori d)Bacillus anthracis

Vibrio cholerae, Helicobacter pylori