Chapter 4: Bacteria and Archaea

Which of the following describes the function of fimbriae?

Adhesion Reason: Yes, fimbriae can stick to other fimbriae and to some surfaces.

Which is true regarding all bacterial cells?

All lack a nucleus.

Which appendage(s) provide motility?

Axial filaments Flagellum

Cylindrical bacterial cells are called _________, whereas gently curved cylindrical cells are referred to as _________

Blank 1: bacillus or rods Blank 2: vibrio

Bacterial __________ is the transfer of genetic material between two bacteria cells.

Blank 1: conjugation

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

Blank 1: glycocalyx

Cocci found in clusters are known as ________-cocci, cocci found in groups of four are known as__________ , and a cubical packet of 8, 16, or more cells is known as a _________

Blank 1: staphylo or micro Blank 2: tetrad or tetrads Blank 3: sarcina

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

Capsule

The greatest variety in bacterial cellular arrangement occurs in which cell type?

Cocci

What is the correct term for describing very short, ovoid, rod-shaped bacterial cells? or The term used for a short, plump bacterial rod is ____________

Coccobacilli

What are the three most common shapes of bacterial cells?

Coccus Bacillus Spirillum

Which of the following statements concerning biofilm is correct?

DNA molecules may be present in biofilms as an attractant to more cells.

Which of the following describes cocci in pairs?

Diplococci

Which of the following are considered external structures of prokaryotic cells?

Flagella Pili

Which appendage(s) provide motility?

Flagellum Axial filaments

Which three structures comprise a bacterial flagellum?

Hook Filament Basal body

The S layer surrounding many bacterial cells is comprised of ______

PROTEIN

Which of the following are types of flagellar arrangements with more than one flagellum?

Peritrichous Amphitrichous Lophotrichous

Which term means that a cell can have various shapes?

Pleomorphic

Which of the following are functions of the glycocalyx?

Protection Adherence

Which of the following structures are possessed by all bacterial cells?

Ribosomes Cell membrane Chromosome(s)

What bacterial cell type is a flexible, spring-like structure?

Spirochete

Which of the following are terms that represent cocci in groups?

Streptococci Tetrads Staphylococci

Which of the following represent arrangements of cocci?

Tetrads Streptococci Sarcina

Which two of the following statements about the bacterial S layer are correct?

The S layer is rarely observed in cells grown in the lab in rich medium. The S layer consists of thousands of copies of a single protein.

Which of the following makes bacteria and archaea different from eukaryotes?

They lack a nucleus.

True or false: Mycoplasmas are pleomorphic because they entirely lack cell walls and thus display extreme variations in shape.

True Reason: Mycoplasmas have no cell wall and therefore can have various shapes which is known as pleomorphism.

Match the letter on each cell type with the correct arrangement of the flagella on that cell.

a matches Choice, monotrichous polar monotrichous polar c matches Choice, lophotrichous polar lophotrichous polar d matches Choice, amphitrichous polar amphitrichous polar b matches Choice, peritrichous peritrichous

In a stratified biofilm, (choose two)

anaerobes are found near the bottom aerobes are found near the surface

A(n) filament is a periplasmic flagellum found in some spirochete bacteria.

axial

Twisting or flexing of spirochete bacteria is attributed to the

axial filaments

A group of cells in a palisade arrangement will have the cellular morphology

bacillus

This image shows cells of Pseudomonas. The best term to describe their cellular morphology is ______.

bacillus Reason: The cells are single, but their morphology is bacillus.

Peptidoglycan is a component of the cell wall in ________.

bacteria

______ 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

In this image of a Gram-positive cell wall, the arrow is pointing to the

cell membrane

Which cell structure is designed to provide shape, support and resistance to osmotic pressure?

cell wall

The prefix "strepto-" is used to indicate that the cells are arranged in ________

chains

During ______, bacterial cells move by flagellar motion in response to chemical signals.

chemotaxis

To move towards a chemical attractant by flagellar motion is referred to as positive ________

chemotaxis

The prefix "staphylo-" is used to indicate that the cells are arranged in:

clusters

The greatest variety in bacterial cellular arrangement occurs in which cell type?

cocci

The genetic transfer of material through pili is termed ______.

conjugation

Biofilms are often stratified, meaning that _________

different microbes occupy spaces that best fit their environmental needs

The prefix "-" means "in pairs."

diplo

The basal body of a flagellum is located

embedded within the cytoplasmic membrane, wall, and outer membrane.

The complex external covering composed of two or three layers found on the majority of bacteria is termed the cell

envelope

Fimbriae, flagella, and pili are all examples of _____ structures found in some bacteria.

external

True or false: The different coccal arrangements are a consequence of growth in broth or on solid media.

false

The cellular appendage indicated by an arrow in this image is a(n) __________

fimbria

Appendages that propel bacterial cells through an aqueous environment include axial filaments and _________

flagella

The basal body, hook, and filament are components of __________ in bacteria.

flagella

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

Which type of cell walls are thicker?

gram positive

Planktonic bacteria

live as single cells, not in biofilm communities

The peptidoglycan component of the cell wall has _____ sugar chains crosslinked by _____ peptide fragments.

long; short

A tuft of flagella from a single site is referred to as a ____________ arrangement, whereas flagella dispersed over the surface of the cell is referred to as ___________

lophotrichous; peritrichous

A typical cell of Staphylococcus would be expected to have a diameter of approximately 1 _________.

micrometer

A cell wall and some form of glycocalyx are found in ______ bacterial cells.

most

Motility refers to an organism's ability to ______.

move

The majority of bacteria have a cell envelope. Which component of the cell envelope is found in only some bacterial cells?

outer membrane

The cell wall in bacteria is primarily composed of

peptidoglycan

When flagella are dispersed randomly over the surface of a bacteria cell the arrangement is referred to as ______.

peritrichous

Capsules protect bacteria against immune cells generally referred to as___________

phagocytes

During _______ , bacterial cells move by flagellar motion in response to light.

phototaxis

Bacteria that live as single cells are described as:

planktonic

The single flagellum attached at one end of each of these cells can best be described as _____.

polar

The functions of the cell wall include

preventing destruction with changes in osmotic pressure maintaining the shape of the bacterium

The two main functions of the glycocalyx are _______ and _______.

protection adherence

The flagellar filament is composed of

protein

Which of the following are components of the peptidoglycan layer of the cell wall? Choose two.

protein carbohydrate

What is the primary function of the capsule?

provides protection

A bacillus is a _____-shaped bacterial cell.

rod

__________ are counterclockwise rotations by flagella that propel a cell forward, whereas __________ are clockwise rotations that cause the cell to stop and change its course.

runs tumble

A _________ is a complex grouping of cells arranged in a cubical packet of 8, 16, or more.

sarcina

A complex arrangement of cells growing in a cubical packet is termed a ______.

sarcina

This image shows cells of Pseudomonas. The best term to describe their cellular arrangement is ______.

single NOT BACILLI....... Reason: The cells are bacilli, but their arrangement is single cells.

A coccus is a ______-shaped bacterial cell.

spherical

A rigid helical bacterial cell twisted twice or more along its axis is described as a(n) ______.

spirillum

The helical structure of a _________ is more rigid than the spring-shaped form of a spirochete.

spirillum

__________ is a flexible, spiral-shaped bacterium.

spirochete

The prefix "-" means "in grape-like clusters."

staphylo

The prefix "_________" means "in a chain".

strepto

Choose the prefixes that may be used to describe arrangements of bacilli. (Choose two.)

strepto- diplo-

What term represents chains of cocci?

streptococci

This image shows part of the peptidoglycan in a bacterial cell wall. The arrow is pointing to a component that is similar to

sugars

In this image of a Gram-positive cell wall, the arrow points to the

teichoic acid

The origin of the various groupings for cocci, for example strepto-, staphylo-, diplo-, is

the geometry of the cell division planes

A curved rod (comma-shaped bacterium) is specifically described as a(n) _______.

vibrio

A gently curved bacterium is specifically described as a(n) ______.

vibrio

The cell shape of the bacteria illustrated in this figure is a ______.

vibrio

In which of the following circumstances do microbes act as a group?

when assembled in a biofilm

Which two of the following situations are opportunities for microbes to act as a group rather than as individuals?

when nanowires are present in a biofilm

A typical cell of Staphylococcus would be expected to have a diameter of approximately

1 μm

order the following events in biofilm formation

1. sticky surface texture attracts single cells 2. colonists attach to the surface 3. receptors, DNA, and other molecules are released as attractants 4. individual cells break off to begin new biofilms