Microbiology chp 11 The Diversity of Bacteria and Archaea

The normal habitat of Bacteroides species in humans includes the ______.

genital tract intestines mouth

Ecophysiology is the study of the ______.

physiological mechanisms bacteria and archaea use to live in terrestrial and aquatic environments

Which of the following can be used to distinguish between members of the genus Bacillus and Clostridium?

their oxygen requirements

Which of the following genera of endospore formers include both obligate aerobes and facultative anaerobes?

Bacillus

Members of the genus Mycoplasma have no cell wall, making them somewhat unique in the microbial world. How do they prevent osmotic lysis?

Their cytoplasmic membrane is rich in sterols to help provide added strength and rigidity.

Which of the following were likely the earliest photosynthesizing organisms?

anoxygenic phototrophs

The motile cells found in sheathed bacteria are called ______ cells, and these exit through the end of the sheath.

swarmer

Prokaryotes that grows well in an environment that contains 32% NaCl would be called extreme

halophiles

Which of the following genera have dormant forms that are resistant to extreme environmental conditions?

Bacillus and Clostridium

Aerobic chemolithotrophs obtain energy by oxidizing reduced inorganic chemicals, using _________ as a terminal electron acceptor.

oxygen

The purpose of the sheath in sheathed bacteria is for ______.

protection

Humans infected with Helicobacter pylori may develop peptic

ulcers

Oxygenic phototrophs use ______ as a source of electrons for reducing power, generating O2.

water

_______ gain energy via the oxidation of reduced inorganic chemicals, using O2 as a terminal electron acceptor.

Aerobic chemolithotrophs

Prosthecate bacteria form projections called prosthecae, which are extensions of the cytoplasm and cell wall. These prosthecae ______.

facilitate absorption of nutrients

Which causes uncontrolled growth of plant tissue, resulting in a tumor?

Agrobacterium

Treponema and Borrelia

are spirochetes.

Chemoorganotrophs oxidize _________ compounds such as glucose to obtain energy.

organic

True or false: Scientists now understand the true diversity of microbial life and have determined the relationships between the millions of prokaryotes that exist.

false

Enterobacteriaceae get their name because they reside in the ______ tract of humans and animals.

intestinal

Obligate aerobes obtain energy using ________ exclusively; none of them can ferment.

respiration

All coliforms are Enterobacteriaceae, but not all Enterobacteriaceae are coliforms.

true

Bacteria that oxidize sulfur are Gram-negative rods or spirals that ______.

use sulfur compounds as an energy source and oxygen as a terminal electron acceptor

Extreme thermophiles are found near ______.

hydrothermal vents volcanic vents hot springs

Archaea are typically found living in extreme environments. An exception to this are the

methanogens

An organism that requires a minimum of 9% NaCl would be called an extreme ______.

halophile

By definition, obligate intracellular parasites cannot ______.

replicate outside of a host cell

A group of Gram-negative bacteria has a spiral shape and a unique motility mechanism that allows them to move through thick, viscous substances. This group is called the

spirochetes

The cells of species in the genus Neisseria are ______.

typically found in pairs Gram-negative cocci

Which of the following organisms is strictly aerobic but can grow anaerobically if nitrogen is present?

Pseudomonas aeruginosa

Which of the following genera of organisms forms a beneficial symbiotic relationship with plants?

Rhizobium

Organisms that form storage granules include ______.

Spirillum Thiomargarita Thioploca

Which of the following is NOT associated with a Clostridium species?

Strep throat

The earliest oxygenic phototrophs probably belonged to a group of bacteria called the

cyanobacteria

Unlike in other anoxygenic phototrophs, in purple bacteria, the components of the photosynthetic apparatus are all located in the cell's _______ membrane.

cytoplasmic

The study of the various adaptations prokaryotes use to survive terrestrial and aquatic environments is called

ecophysiology

Corynebacterium species and Enterobacteriaceae family members are examples of ______ anaerobes, meaning that they preferentially use aerobic respiration if O2 is available, but can ferment if it is not.

facultative

An anaerobic chemoorganotroph that uses glucose for energy and pyruvate as its terminal electron acceptor is performing ______.

fermentation

Members of the Gram-negative genera Aquifex and Hydrogenobacter are hydrogen-oxidizing bacteria. An example of their metabolism involves using ______.

hydrogen as a source of energy and oxygen as a terminal electron acceptor, forming water

Complex structures called fruiting bodies are a characteristic of

myxobacteria

Many cyanobacteria can convert nitrogen gas (N2) to ammonia, which is a process called ______.

nitrogen fixation

Aerobic chemoorganotrophs gain energy via the _______, using O2 as a terminal electron acceptor.

oxidation of organic compounds

As a group, chemolithotrophs ______ to obtain energy.

oxidize reduced inorganic chemicals such as hydrogen gas

The purple bacteria are Gram-negative organisms that can appear ______ due to their light-harvesting pigments.

red orange purple

Scientists are interested in studying the growth of extreme _________, archaea that grow near volcanic vents and fissures because these conditions are thought to mimic early earth's environment.

thermophiles

Which of the following about Mycoplasma is FALSE?

they are killed by penicillin

______ species are Gram-negative, strictly anaerobic, make up about a third of the bacteria in fecal matter in humans, and are associated with abscesses and bloodstream infections.

Bacteroides

The two most common genera of Gram-positive rod-shaped bacteria that form endospores are ______.

Clostridium Bacillus

Sulfur-oxidizing bacteria ______.

can sometimes grow in filaments can use hydrogen sulfide or thiosulfate as an energy source

Campylobacter jejuni infections are commonly associated with ______.

diarrhea

Of the various types of dormant cells, the ______ is the most resistant to environmental extremes.

endospore

Like the green and purple bacteria, members of the genus Heliobacterium are also examples of anoxygenic phototrophs. They are ______ bacteria related to members of the genus Clostridium.

endospore-forming rod-shaped Gram-positive

Staphylococcus epidermidis is part of the normal microbiota of the

skin

The ________ bacteria have projections called prosthecae, which are extensions of the cytoplasm and cell wall that increase the surface area to facilitate absorption of nutrients.

prosthecate

A group of bacteria called green bacteria are ______.

Gram-negative

Hydrogen-oxidizing bacteria such as Aquifex and Hydrogenobacter are ______.

Gram-negative obligate chemolithotrophs thermophilic

Members of the family Enterobacteriaceae are _______.

Gram-negative rods

Spirochetes are bacteria that are ______ and possess a unique mechanism of _______.

Gram-negative; motility

Endospore-forming bacteria are typically ______.

Gram-positive rods

During photosynthesis, anoxygenic phototrophs use _______ as a source of electrons to make reducing power.

H2S

Aside from green and purple bacteria, Gram-positive endospore forming rods of the genus ______ are also anoxygenic phototrophs.

Heliobacterium

Members of this group of microbes can break down glycogen deposited in the vaginal lining in response to estrogen. This helps to drop the pH in the area, preventing infections.

Lactic acid bacteria

Which of the statements about chemotrophs is FALSE?

Lactic acid bacteria such as Lactobacillus obtain their ATP by oxidizing glucose, using lactic acid as their terminal electron acceptor.

Bacteria in aquatic environments have evolved various mechanisms to maximize nutrient uptake and retention. Why?

Most aquatic environments lack a steady supply of nutrients.

Which of the following bacteria can oxidize large amounts of ammonia-containing waste, consuming so much oxygen in the process that they can create hypoxic areas of water?

Nitrifying bacteria

Cyanobacteria have evolved elaborate mechanisms for preventing O2 from coming into contact with the nitrogenase enzyme. Why?

Nitrogenase enzyme complexes are damaged or destroyed by O2.

A reason why environments that are routinely exposed to O2 can support anaerobic growth is that ______.

O2-consuming organisms depletes the oxygen levels

I say: "Gram-negative bacteria, that are typically kidney-bean-shaped cocci in pairs. You say:

"Neisseria"

Approximately 99% of the microbes in the intestines are obligate anaerobes. We have plenty of blood vessels that can bring oxygen to the tissues of the intestines. Why would there be obligate anaerobes within these areas?

The inside space of the intestines is highly anaerobic. It is deep inside the body where oxygen cannot reach and it is not supplied with blood.

What distinguishes Staphylococcus, species from Streptococcus, Enterococcus and Lactococcus species?

The production of catalase.

Bdellovibrio species ______.

bore a hole in the cell wall of their prey prey on Gram negative bacteria like E. coli are highly motile Gram-negative curved rods

Cyanobacteria as a group are capable of ______.

both photosynthesis and nitrogen fixation

How do aerobic chemoorganotrophs obtain their energy?

by oxidizing organic compounds by using O2 as a terminal electron acceptor

As a group, anaerobic chemoorganotrophs ______.

can obtain energy via fermentation produce ATP via substrate level phosphorylation

The purpose of storage granules produced by some bacteria is to store ______.

nutrients

Which of the following correctly describe relationships between genera of bacteria and their means for obtaining nutrients from plants?

Agrobacterium species are plant pathogens that cause tumor-like growths. Rhizobium species form a mutually beneficial relationship with certain types of plants.

Extreme halophiles/extreme thermophiles are members of the domain ______.

Archaea

_________ species are Gram-negative curved rods that are highly motile and prey on other Gram-negative rods by boring a hole in their cell wall.

Bdellovibrio

How do anoxygenic phototrophs benefit from having accessory pigments that allow light to be harvested at deeper areas of a moist or aquatic environment?

This allows even anaerobic microbes to conduct photosynthesis, as they can harvest light energy in the deeper areas where oxygen won't be present, use wavelengths of light not absorbed by the photosynthetic organisms closer to the surface of the water; AND don't have to compete with other cells that use oxygen in the upper levels for the scarce nutrients in the fluid environment.

Which of the following statements about microbial diversity is true?

We are only now beginning to understand the diversity of prokaryotes.

In addition to being photosynthetic, many cyanobacteria have the ability to convert nitrogen gas (N2) into ______, a process known as nitrogen fixation.

ammonia

Chemoorganotrophs that perform ______ often use sulfur or sulfate as a terminal electron acceptor.

anaerobic respiration

An organism found in an environment that is very hot and acidic is most likely a member of the domain

archaea

Characterized members of the domain ______ typically thrive in extreme environments, such as high heat, acidity, alkalinity, and salinity.

archaea

Most of the anaerobic chemolithotrophs that have been discovered are members of what domain?

archaea

Nitrifiers can be described as bacteria that ______.

are Gram-negative obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrite

In a healthy individual, anaerobes can regularly be found on and in the ______.

intestinal tract oral cavity skin

The green bacteria are Gram-_________ organisms that are typically green or brownish in color.

negative

An organism that cannot reproduce outside of a host cell is termed an _______ _______ parasite.

obligate intracellular

Nitrogen fixation, or the process of converting nitrogen gas (N2) into ammonia, is an exclusive ability of ______.

prokaryotes

A diverse group of Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrate are known as

nitrifiers

How do obligate aerobes obtain energy?

using respiration only

Which of the following bacteria is typically a harmless resident of the skin?

Staphylococcus epidermidis