Micro ch 4 quiz

The cortex is formed from _____.

peptidoglycan

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

protein

The cell membrane is composed of _____________.

proteins dispersed throughout a phospholipid bilayer

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

Which of the following conditions need to be suitable for bacteria to grow?

All of these are examples of conditions that need to be suitable for bacterial growth

Which of the following is/are prone to biofilm accumulation?

All these structures are prone to biofilm accumulation.

How long can spores survive?

Millions of years

Biofilms are found:

On a variety of surfaces including shower curtains, the walls of swimming pools and teeth

Which of the following diseases is NOT caused by a spore-forming bacterium?

Strep throat: Streptococci do not form spores, whereas Bacillus anthracis, Clostridium tetani, and Clostridium botulinum are all members of spore-forming genera.

Peptidoglycan; cell membrane

Both gram-positive and gram-negative cells

Which of the following is true of biofilms?

They can lead to systemic infections

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

A spirochete moves in a screw-like manner that is mediated by axial fibrils located in the cell's periplasmic space.

True

Biofilms typically do not develop on healthy tissue

True: Biofilms tend to accumulate on damaged tissues.

True or False: Encapsulated bacterial cells generally have greater pathogenicity.

True: Capsules protect bacteria from phagocytes, enhancing their pathogenicity in most cases.

When is sporulation initiated by spore-forming bacteria?

When nutrients are depleted or conditions become adverse

A vegetative cell is:

a metabolically active cell

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

calcium, water

The developing spore is surrounded by:

the membrane of the mother cell

Please select all of the statements that are true about endospores. Bacterial endospores are highly resistant to heat, drying and radiation. Endospores are only found in the environment and are not medically relevant. 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. Endospores can be formed by any genus of bacteria.

-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.

Which of the following correctly describe the color of different cells after using the Gram staining technique? Gram-negative--purple Gram-negative--pink/red Gram-positive--purple Gram-positive--pink/red

-Gram-negative--pink/red -Gram-positive--purple

Please select all of the characteristics that define life and living things. Heredity Sexual reproduction Growth and development Use of energy Increase in size

-Heredity -Growth and development -Use of energy

Please select all of the following which are found in all cells regardless of cell type. cell membrane cell wall cytoplasm DNA organelles

-cell membrane -cytoplasm -DNA

Please select all of the following which are contents of the cell cytoplasm. chromosome ribosome water glycocalyx fimbriae

-chromosome -ribosome -water

Which of the following is considered an "adverse condition" by most bacteria?

A pH of 4 is very acidic and not hospitable for most bacteria.

Flagella

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

Biofilms are often more sensitive to antibiotics.

False: Biofilms are often impervious to antibiotics.

True or False: Most bacterial genera are capable of forming endospores.

False: Endospores are produced by the genera Bacillus, Clostridium, and Sporosarcina.

True or False: Biofilms are composed of a single bacterial species.

False: False, in the natural environment biofilms often consist of different types of organisms that function together in the cycling of nutrients.

True or False: When a spore germinates, it gives rise to 2 vegetative cells.

False: When a spore germinates, it gives rise to one vegetative cell.

True or False: When the bacterial glycocalyx is easily removed, it is called a capsule.

False: When the bacterial glycocalyx is easily removed, it is called a slime layer

True or False: Endospores function in the reproduction of bacterial genera such as Bacillus and Clostridium.

False: While endospores are produced by these genera, they do NOT function in reproduction because no increase in cell number occurs. Instead, they are structures aimed at ensuring survival.

Lipopolysaccharide; outer membrane

Gram-negative cells

Teichoic acid

Gram-positive cells

Microenvironments are created within the biofilm based on:

The availability of gases such as oxygen, nutrient concentrations and pH levels all can vary within the biofilm, leading to the recruitment of specific bacteria that can grow under these conditions.

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

The production of which substance leads to thickening of the biofilm over time?

exopolymer

Which of the following structures leads to reversible binding of bacterial cells to a surface?

fimbriae and flagella

Which of the following surfaces have nutrients available that encourage the development of biofilms?

moist abiotic surfaces and biotic surfaces such as plant and animal tissue

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

mother cell

The primary function of flagella is for ______.

motility