C15-C21

Question 1

Anoxygenic photosynthesis is
present in six bacterial phyla:

Answer 1

Proteobacteria, Chlorobi, Chloroflexi,
Firmicutes, Acidobacteria, and Gemmatimonadetes

Question 2

Oxygenic photosynthesis, by contrast, is known only within the

Answer 2

Cyanobacteria

Question 3

Cyanobacteria key genera:

Answer 3

Prochlorococcus, Crocosphaera, Synechococcus,
Trichodesmium, Oscillatoria, Anabaena

Question 4

Cyanobacteria morphological groups: unicellular, dividing by binary fission

Answer 4

Chroococcales

Question 5

Cyanobacteria morphological groups: unicellular, dividing by multiple fission
(colonial)

Answer 5

Pleurocapsales

Question 6

Cyanobacteria morphological groups: filamentous nonheterocystous forms

Answer 6

Oscillatoriales

Question 7

Cyanobacteria morphological groups: filamentous,
divide along a single axis, and are capable of cellular differentiation

Answer 7

Nostocales

Question 8

Cyanobacteria morphological groups: morphologically similar
to Nostocales except that cells divide in multiple planes, forming
branching filaments

Answer 8

Stigonematales

Question 9

a lineage of unique unicellular Cyanobacteria once thought to be
distinct but now classified within the Chroococcales.

Answer 9

prochlorophytes

Question 10

cyanobacteria morphology; short, motile filaments that
break off from longer filaments to facilitate dispersal in times of
stress.

Answer 10

hormogonia

Question 11

cyanobacteria morphology; resting structures which protect the organism during periods of darkness, desiccation, or cold/

Answer 11

akinetes

Question 12

cyanobacteria morphology; copolymer of aspartic acid and arginine and is a nitrogen storage product; when nitrogen in the environment becomes
deficient, it is broken down and used as a cellular nitrogen source.

Answer 12

cyanophycin

Question 13

Purple sulfur bacteria key genera;

Answer 13

Chromatium, Thermochromatium, Ectothiorhodospira

Question 14

anoxygenic phototrophs that use hydrogen sulfide (H2S) as an electron donor for photosynthesis

Answer 14

purple sulfur bacteria

Question 15

purple non-sulfur bacteria key genera;

Answer 15

Rhodospirillum, Rhodoferax, Rhodopseudomonas,
Rhodobacter

Question 16

the most metabolically versatile of all microbes; not always
purple; these organisms synthesize an array of carotenoids

Answer 16

Purple nonsulfur bacteria

Question 17

One interesting characteristic shared by all species of purple nonsulfur bacteria

Answer 17

presence of a “photosynthetic gene
cluster” (PGC); set of several connected operons
whose genes encode the necessary proteins to carry out anoxygenic
photosynthesis

Question 18

Aerobic Anoxygenic Phototrophs key genera

Answer 18

Roseobacter, Erythrobacter

Question 19

obligatory aerobic heterotrophs that use light as a supplemental source of energy to support growth; strict heterotrophs and employ anoxygenic photosynthesis only
under oxic conditions as a supplemental source of energy; unable to fix CO2 and thus rely on organic
forms of carbon as their carbon source.

Answer 19

aerobic anoxygenic phototrophs

Question 20

Green Sulfur Bacteria key genera

Answer 20

Chlorobium, Chlorobaculum, Prosthecochloris,
“Chlorochromatium”

Question 21

coherent group of
anoxygenic phototrophs that forms the phylum Chlorobi; have little metabolic versatility, and they are typically
nonmotile and strictly anaerobic anoxygenic phototrophic bacteria.
The group is also morphologically restricted and includes primarily
short to long rods

Answer 21

Green sulfur bacteria

Question 22

green sulfur bacteria; a marine species whose cells form extensions of the cytoplasm
and cell wall called prosthecae

Answer 22

Prosthecochloris

Question 23

Green Nonsulfur Bacteria; key genera

Answer 23

Chloroflexus, Heliothrix, Roseiflexus

Question 24

also called filamentous anoxygenic phototrophs, are anoxygenic phototrophs of the phylum Chloroflexi; All cultured representatives are filamentous bacteria that are capable of gliding motility.

Answer 24

green nonsulfur bacteria

Question 25

Heliobacteria key genera

Answer 25

Heliobacterium, Heliorestis

Question 26

phylogenetically coherent group of phototrophic gram-positive Bacteria found within the phylum Firmicutes; are anoxygenic phototrophs that
have an FeS-type photosystem and that produce a
unique pigment, bacteriochlorophyll g; form rod-shaped or filamentous cells

Answer 26

heliobacteria

Question 27

Acidobacteria key genus

Answer 27

Chloracidobacterium

Question 28

a thermophilic oxygen-tolerant anoxygenic phototroph of the
phylum Acidobacteria

Answer 28

Chloracidobacterium thermophilum

Question 29

Gemmatimonadetes key genus

Answer 29

Gemmatimonas

Question 30

phototrophic acidobacteria; A novel group of anoxygenic phototrophs has been discovered growing in photosynthetic microbial mats of certain thermal springs in
Yellowstone National Park (USA)

Answer 30

Chloracidobacterium

Question 31

Phototrophic Gemmatimonadetes; Another novel group of anoxygenic phototrophs has been discovered
in a freshwater lake in the western Gobi desert (part of China and Mongolia).

Answer 31

Gemmatimonas

Question 32

an aerobic facultative photoheterotroph of the phylum Gemmatimonadetes. It gains most of its
energy through the aerobic respiration of organic compounds,
whether in the light or in the dark; However, in the light, it uses photophosphorylation to supplement energy generated by aerobic respiration

Answer 32

Gemmatimonas phototrophica

Question 33

530-532