Deck 24: Actinobacteria: the High G-C Gram-Positive Bacteria

Question 1

Actinomycetes degrade a variety of organic compounds and are,therefore,important in mineralization processes in the environment.

Answer 1

True

Question 2

Members of the genus Actinomyces are either facultative or strict anaerobes that require ________ for optimal growth.
or

Answer 2

carbon dioxide CO2

Question 3

Although the spores of actinomycetes are not as heat resistant as endospores,the extent of heat resistance they demonstrate can be used to help classify these organisms.

Answer 3

True

Question 4

Members of the genus Actinomyces are either straight or slightly curved rods,or slender filaments with true branching.

Question 5

Features considered taxonomically important to the actinomycetes include peptidoglycan composition and structure,and morphology and color of mycelia and sporangia.

Question 6

A(n)_____________ mycelium is a branching network of filaments that rises above the agar growth medium.

Question 7

The sexual spores of actinomycetes are called sporangiospores.

Question 8

A distinguishing characteristic of actinomycetes that can be used to classify these organisms is the types of sugars found in extracts of the organisms.

Question 9

The actinomycetes are capable of degrading a wide variety of organic compounds.

Question 10

Although actinomycetes vary in many ways,they all share a common type of cell wall.

Question 11

A(n)_____________ mycelium is a branching network of fibers on and/or beneath the surface of the agar growth medium.

Question 12

Although the actinomycetes are generally nonmotile,the spores may be flagellated and,therefore,motile.

Question 13

Actinomycete spores are usually formed on __________ mycelia.

Question 14

The genus Arthrobacter has a distinctive growth cycle in which branched rod-shaped bacteria are produced in the exponential phase,and cocci are found in stationary phase cultures.

Question 15

Members of the genus Micrococcus are frequently pigmented and may grow in yellow,red,or orange colonies.

Question 16

Actinomycetes produce many of the antibiotics we use in medicine.

Question 17

Septa divide the actinomycete mycelia into cells,each containing a single nucleus.

Question 18

Actinomycetes are Gram-positive,spore-forming bacteria.

Question 19

Septa divide the actinomycete mycelia into long cells each containing several nucleoids.

Question 20

Actinoplanetes have extensive __________ mycelia.

Question 21

Actinomycetes form

A)substrate mycelia and aerial mycelia.
B)heat resistant endospores.
C)prostheca with holdfasts.
D)a sheath made of polysaccharides and proteins.

Question 22

Some of the high G + C Gram-positive bacteria such as Arthrobacter divide by means of snapping division.

Question 23

Members of the genus Mycobacterium are said to be ______-_____ because basic fuchsin dye cannot be removed even with acid-alcohol treatment.
or

Question 24

The maduromycetes differ from other high G + C Gram-positives in that they contain the sugar madurose in cell extracts.

Question 25

Nocardia cause biodeterioration of rubber joints in water and sewer pipes.

Question 26

The special structure in which some actinomycetes form their spores is called a _____.

A)sporangium
B)conidium
C)sporatorium
D)basidium

Question 27

The streptomycetes form spores on their substrate mycelia.

Question 28

Which of the following is true of the actinomycetes?

A)They divide by budding.
B)They closely resemble the fungi in morphology.
C)Some are photosynthetic.
D)They are unique among prokaryotes in producing sexual spores.

Question 29

The medically useful compounds some actinomycetes produce when forming aerial mycelia are called ______.

A)anti-metabolites
B)primary metabolites
C)secondary metabolites
D)inhibitory metabolites

Question 30

Which of the following can be used to help classify actinomycetes?

A)Cell wall composition
B)Percent G + C content
C)Phospholipid composition of the membrane
D)All of these can be used to classify actinomycetes.

Question 31

Bifidobacterium bifidum is a major pathogen in breast-fed babies.

Question 32

Most actinoplanetes are found in marine habitats.

Question 33

None of the nocardioform actinomycetes are pathogenic to humans.

Question 34

Which of the following is(are)true about actinomycete spores?

A)They are heat resistant.
B)They withstand desiccation well.
C)They are true bacterial endospores.
D)They are all motile due to the presence of a flagellum.

Question 35

Of the nearly 150 species in the genus Streptomyces,only S.somaliensis is known to be pathogenic in humans.

Question 36

Actinomycetes are usually found in __________ habitats.

A)soil
B)freshwater
C)marine
D)medical

Question 37

Actinomycetes

A)form asexual spores.
B)form sexual spores,that is,they are used for sexual reproduction.
C)form heat resistant spores.
D)do not form spores.

Question 38

Actinoplanetes that dwell in the soil play an important role in plant and animal decomposition.

Question 39

A few species of actinomycetes have been found to be pathogenic in humans,other animals,and plants.

Question 40

Actinomycete spores formed within a special structure are called ______.

A)endospores
B)conidiospores
C)sporangiospores
D)myxospores

Question 41

The genus Frankia

A)grows in symbiotic association with the roots of some higher plants and fixes nitrogen.
B)produces heat-resistant endospores.
C)is strictly a marine bacterium.
D)produces heat resistant endospores and is strictly a marine bacterium.

Question 42

Members of the genus Thermomonospora

A)produce single spores on their mycelia.
B)spores can form on either aerial or substrate mycelia.
C)can be isolated in compost piles and hay.
D)All of the choices are correct.

Question 43

Nitrogen fixation by Frankia bacteria is efficient enough to allow alder trees to grow in the absence of combined nitrogen.

Question 44

The streptomycetes form spores by division of the cells of the aerial mycelia in

A)a single division plane.
B)two division planes simultaneously.
C)two division planes consecutively.
D)multiple division planes.

Question 45

The genus Arthrobacter

A)is a significant component of the microbial flora of soil.
B)plays an important role in the degradation of some herbicides and pesticides.
C)forms heat resistant endospores.
D)is a significant component of the microbial flora of soil and plays an important role in the degradation of some herbicides and pesticides.

Question 46

Which of the following antibiotics is produced by bacteria in the genus Streptomycetes?

A)Vancomycin
B)Tetracycline
C)Chloramphenicol
D)All of the choices are correct.

Question 47

Overgrowth of the skin bacterium Proprionibacterium acnes may lead to _____.

A)body odor
B)bloodstream infection
C)warts
D)rash

Question 48

Which of the following antibiotics is (are)produced by actinoplanetes?

A)Nalidixic acid
B)Gentamicin
C)Cycloserine
D)Penicillin

Question 49

Members of the genus Micrococcus usually exist as ______.

A)pairs
B)tetrads
C)irregular clusters
D)All of the choices are correct.

Question 50

Nocardia are typically found in which of the following environments?

A)Soil
B)Intestinal tract of warm-blooded animals
C)Geothermally heated springs
D)Root nodules of some higher plants

Question 51

The actinoplanetes can be found in _______ habitats.

A)soil
B)freshwater
C)marine
D)All of the choices are correct.

Question 52

Which of the following is correct about members of the genus Propionibacterium?

A)They are used in the production of Swiss cheese.
B)They cause acne vulgaris and contribute to the development of body odor.
C)They are typically found growing on the skin and in the digestive tract of animals.
D)All of the choices are correct.

Question 53

Species of the genus Corynebacterium

A)form helical-shaped cells.
B)sometimes divide to form characteristic club-shaped cells.
C)are harmless saprophytes.
D)form elongated rod-shaped cells.

Question 54

Diphtheria is caused by a member of which of the following genera?

A)Mycobacterium
B)Corynebacterium
C)Propionibacterium
D)Nocardia

Question 55

Members of the genus Mycobacterium cause which of the following diseases in humans?

A)Tuberculosis and leprosy
B)Abscesses
C)Diphtheria
D)Meningitis

Question 56

The genus Mycobacterium ______.

A)are strict anaerobes and catalase positive
B)have cell walls similar to Gram-negative bacteria
C)stain acid-fast
D)are strict anaerobes and catalase positive and have cell walls similar to Gram-negative bacteria

Question 57

The spores of streptomycetes are

A)motile by means of flagella.
B)motile by means of cilia.
C)motile by means of pseudopodia.
D)nonmotile.

Question 58

Species of the genus Gardnerella

A)are thought to be a major cause of bacterial vaginitis.
B)are motile spore-forming cocci.
C)are normal flora found on the skin of humans.
D)All of the choices are correct.

Question 59

The skin infection streptothrichosis is caused by members of the genus ______.

A)Streptomyces
B)Dermatophilus
C)Streptococcus
D)Propionibacterium

Question 60

Members of the genus Micrococcus are usually ______.

A)aerobic
B)anaerobic
C)facultatively anaerobic
D)microaerophilic

Question 61

Bifidobacteriales are best characterized as Gram-positive,motile,spore-forming rods.

Question 62

Bacteria can act as probiotic agents,such as species of _____ added to yogurt,to help impart health effects to the intestinal tract.