Micro ch 4 Assignment Q's

The cortex is formed from _____.

peptidoglycan

Please select all of the following which are found in all cells regardless of cell type.

Cell membrane, cytoplasm, DNA

True or False: The thinner peptidoglycan layer of gram-positive bacteria allows the crystal-violet-iodine complex to leave the cell.

False

When is sporulation initiated by spore-forming bacteria?

when nutrients are depleted or conditions become adverse

The functions of the cell envelope include

Helping to determine the shape of a bacterial cell. Preventing rupture of the cell from increased internal pressure. Allowing the cell to regulate the transport of many molecules from the internal to external environment.

Of the photosynthetic bacteria, cyanobacteria produce ______ as a product of photosynthesis but the green and purple sulfur bacteria do not produce this substance.

Oxygen

In the final step of spore formation a _____ coat forms around the cortex.

Protein

Cytoskeleton

This structure is a network of protein polymers that helps stabilize the shape of the cell from within.

Granules

This structure stores inorganic compounds, such as sulfur and polyphosphate.

Inclusion bodies

This structure stores nutrients during periods of ample resources to compensate for times when nutrients are scarce.

Halophile

an organism that lives in an environment that contains high amounts of salt such as the Dead Sea

hyperthermophile

an organism that lives in extremely hot temperatures such as the hot springs of Yellowstone National Park

psychrophile

an organism that lives in very cold conditions, including temperatures below freezing

Archaea

are novel prokaryotic organisms that belong to their own superkingdom (domain).

The bacterial flagellum moves

by rotation that is powered by the proton motive force.

In the next phase of spore formation, _____ enters the cortex and _____ leaves the cortex.

calcium; water

A taxonomical outline of bacterial species based on shared evolutionary histories would be described as a

phylogenetic system.

This arrangement is formed when rod-shaped bacteria divide multiple times on their transverse planes and do not separate therefore the cells continue to be attached to each other.

streptobacilli

Please select all of the statements that are true about endospores.

-Bacterial endospores are highly resistant to heat, drying, and radiation. -Endospores can exist in the environment for indefinite periods of time. -Endospores resist boiling and therefore steam must be used to destroy endospores present in food.

Please select all of the following which are purposes of classification and taxonomy in the study of prokaryotes

-Classification and taxonomy can assist in identifying an unknown organism. -Classification and taxonomy can assist in studying the evolutionary origins of an organism. -Classification and taxonomy can assist in identifying a new species of organism.

Please select all of the following that are characteristics of archaea.

-prokaryotic -circular chromosome -contain long-chain, branched hydrocarbons in the cell membrane

Please select all of the characteristics that define life and living things

-the ability to synthesize new cell components or release energy through chemical reactions the ability to synthesize new cell components or release energy through chemical reactions -ability to respond to their environment ability to respond to their environment -ability to control the flow of some materials across cell boundaries

Which term(s) refer to cells without cell walls?

Mycoplasma sphereoplast protoplast

Please order the following choices to reflect the generalized anatomy of bacterial cells with "1" being the innermost cell component and "4" being the outermost cell component.

1. Cytoplasmic matrix 2. Cell membrane 3. Cell wall 4. glycocalyx

Please select all of the following which are contents of the cell cytoplasm.

Chromosome Ribosome Water

The best understood bacterial cytoskeletons are composed primarily of

Actin

After Gram's iodine is added, what color do the cells appear under a light microscope?

All cells appear purple

The cell envelope is the external covering that lies outside of the cell cytoplasm and is composed of the _______ and _______.

Cell membrane and cell wall

Ribosome

Composed of RNA and protein, this structure synthesizes new proteins.

Excess nutrients that the cell may store for later use may be found within

Cytoplasmic granules

Although they share many bacterial characteristics, members of the Domain Archaea are more closely related to Domain ? than to bacteria.

Eukarya

Characteristics that define archaea, however, include the presence of unique membrane ?, cell wall construction and composition and metabolic pathways.

Lipids

When spore formation begins, the vegetative cell is referred to as the ________.

Mother cell

Why must fresh cells be used when performing a Gram stain?

Old cells may not Gram stain properly.

For example, both archaea and eukaryotes share unique ? RNA sequences and their ribosomal subunit structures are similar as well.

Ribosomal

Ribosomes function primarily to

Synthesize protiens

This arrangement is formed when a coccus divides on perpendicular planes and results in four cocci being attached as a cluster of cells.

Tetrad

Chromosome

The structure which contains the essential DNA of the cell.

Plasmid

The structure which contains the nonessential DNA of the cell.

Which of the following explains why archaeons are extremophiles?

They are ancient, primitive organisms that adapt well to extreme conditions because they have retained characteristics of the cells that first evolved when Earth's conditions were far more extreme.

Acid fast cells

cells which contain a thick layer of mycolic acid or cord factor

Gram positive cells

cells which contain a thick layer of peptidoglycan and teichoic acids

Gram negative cells

cells which contain both an inner and outer membrane as well as a thin layer of peptidoglyan

Mycoplasms

cells which lack a cell wall with peptidoglycan but contain sterols to strengthen their cell membrane

The two groups of obligate intracellular bacteria are the ________, usually spread by contact, and the ________, usually transmitted by the bites of arthropods.

chlamydias; rickettsias

Flagella

composed of a filament, hook and basal body, these cell appendages provide movement to the cell

This arrangement is formed when two rod-shaped bacteria divide on the transverse plane and do not separate.

diplobacilli

This arrangement is formed when a coccus divides on a single plane and the two daughter cells remain attached.

diplococci

Which of the following correctly describe the color of different cells after using the Gram staining technique?

gram-negative—pink/red gram-positive—purple

Please select all of the characteristics that define life and living things.

heredity, growth and development and use of energy

Other than maintaining the shape of the cell, what is the primary function of the cell wall, and which component contributes most to this function?

maintaining strength; peptidoglycan

Bacterial species are defined in a fundamentally different way than mammalian species are. This is because

mammals reproduce sexually while bacteria reproduce asexually

This arrangement is formed when bacilli that are attached end to end fold back on each other to form rows of side-by-side cells.

palisades arrangement

The cell membrane is composed of _____________.

proteins dispersed throughout a phospholipid bilayer

When ethanol is applied correctly, gram-positive cells appear ____ and gram-negative cells appear _____.

purple; colorless

Choose the answer that best completes this statement's blanks in the correct order. When all the flagella on a cell rotate in a counterclockwise fashion, the cell is propelled forward in a movement known as a ____, but when the flagella reverse direction, the cell stops and changes course in an action known as a ____.

run; tumble

The developing spore is surrounded by

the membrane of the mother cell.

Such adaptations to their metabolic pathways allow archaea to live in extreme environments, such as areas with high levels of salt (halophiles) or high temperatures (?).

thermophiles

Axial filaments

these long, coiled threads provide movement to spirochetes

Pili

these long, tubular appendages allow cells to conjugate to other cells

Fimbriae

these short, bristle-like projections are used to attach the cell to other cells or surfaces

genetic techniques

these tests use DNA to determine the identity of an organism

serological analysis

these tests use antibody reactions to identify an organism or to determine relatedness

Morphology

these tests use cell shape and Gram reaction to classify organisms

bacterial physiology/biochemistry

these tests use the presence or absence of biochemical processes and enzymes to group organisms

glycocalyx

this is the general term which describes all the various coatings covering the surface of the cell

Capsule

this layer of polysaccharides and/or proteins is tightly bound to the cell and contributes to the cell's pathogenicity

Slime layer

this loosely attached, thin mucoid layer protects the cell from drying out or losing nutrients

peritrichous

this pattern consists of flagella randomly distributed around the cell

amphitrichous

this pattern has flagella at both poles of the cell

lophotrichous

this pattern has groups of flagella all originating from the same point on the cell

monotrichous

this pattern has one flagellum attached at one end of the cell

Polar

this type of flagella can be found at either or both ends of a cell

The primary function of the cell membrane is

to regulate the transport of molecules in and out of the cell.