Microbial Ecology (#5) Flashcards
(105 cards)
1
Q
cyanobacteria that make biofilms called “microbial mats;” found in pre-cambrian rocks (extremely old) and still form today
A
stromatolites
2
Q
where found the first microbial fossils
A
in microbial mats (made by stromatolites)
3
Q
the study of the relationships of organisms between each other and their environment
A
ecology
4
Q
sum of all the organisms and abiotic (nonliving) factors in a particular environment (ex: ocean, forests, desert, lakes)
A
ecosystem
5
Q
every ecosystem has _____
A
microbes
6
Q
T/F: some ecosystems are EXCLUSIVELY microbes
A
true (ex: boiling hotspring)
7
Q
portion of an ecosystem where a community could reside
A
habitat
8
Q
habitat =
A
PLACE
9
Q
relationships where 2 organisms live in conjunction
A
symbiotic relationships
10
Q
type of symbiotic relationships (3):
A
- parasitism
- mutualism
- commensalism
11
Q
type of symbiotic relationship: one organism HURTS the other
A
parasitism
12
Q
type of symbiotic relationship: both organisms benefit from each other
A
mutualism
13
Q
type of symbiotic relationship: one benefits while the other is not affected
A
comensalism
14
Q
a group of organisms of the SAME species in the SAME place at the SAME time
A
population
15
Q
metabolically related microbial populations (many populations); ex: species that all use photosynthesis
A
guild
16
Q
a habitat shared by a guild
A
niche
17
Q
best niche for an organism; organisms DOMINATES this niche; every organism has one
A
prime niche
18
Q
prime niche is also called:
A
realized niche
19
Q
two or more cell populations coexisting in a certain area (habitat) at given time
A
community
20
Q
order of ecological concepts from largest —> smallest (5):
A
- ecosystem (LARGEST)
- community
- guild
- population
- individual (smallest)
21
Q
diversity =
A
variety
22
Q
types of diversity (3):
A
- alpha diversity
- beta diversity
- gamma diversity
23
Q
type of diversity: diversity WITHIN a single community (sample); can get a good look at what’s happening within a habitat
A
alpha diversity
24
Q
components of alpha diversity (3):
A
- richness
- abundance
- evenness
25
component of alpha diversity: the total number of different SPECIES present in a particular area
richness
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component of alpha diversity: the PROPORTION of each species
abundance
27
component of alpha diversity: how similar the abundances are (relative abundance of different species); 4 red to 6 green
evenness
28
alpha diversity classification: lots of different species and evenly proportioned
rich and even
29
alpha diversity classification: a lot of different species, but one dominates the others
rich, not even
30
alpha diversity classification: only has one single species
not rich or even
31
type of diversity: COMPARISON of samples (between community diversity); more mathematical comparison
beta diversity
32
type of diversity: the total species diversity for the different ecosystems within a region
gamma diversity
33
gamma diversity is also called _______ diverstity
landscape diversity
34
if you see: A vs B has 8 species, what kind of diversity are you looking at?
beta (is comparing A vs. B)
35
what 2 things can alter diversity?
resources + conditions
36
alteration of diversity examples: macronutrient, micronutrients, oxygen and other e- acceptors, inorganic e- donors
resources
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alteration of diversity examples: temperature, water potential, pH, oxygen, light, and osmolarity
conditions
38
as you go down into anoxic sediments, you get less and less favorable _____ _______; not able to make as much ATP
electron acceptors
39
Legumes don't need nitrogen fertilizers bc rhizobia in their root nodules fix _____ into ______
nitrogen into ammonia
40
study of biologically mediated chemical transformations
biogeochemistry
41
biogeochemistry involves the many ______ of activities (of essential elements) carried out by microbes
recylcing
42
biogeochemical cycles (4):
- carbon
- nitrogen
- sulfur
- iron
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nitrogen cycle processes (5):
1) nitrification
2) denitrification
3) nitrogen fixation
4) ammonification
5) anammox
44
nitrogen cycle process: the oxidation of AMMONIA to NITRATE; might take 2 steps
nitrification
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nitrogen cycle process: the reduction of NITRATE to NITROGEN GAS (N2); bad for soils + plants bc N2 in the atmosphere is unavailable to plants
denitrification
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nitrogen cycle process: the reduction of NITROGEN GAS (N2) to AMMONIA; putting N into a form we can use
nitrogen fixation
47
nitrogen cycle process: the release of ammonia during the decomposition of organic nitrogen compounds (dead plants + animals)
ammonification
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nitrogen cycle process: the anaerobic oxidation of AMMONIA to NITROGEN GAS (N2); denitrification but anaerobic
anammox
49
major reservoir of nitrogen =
atmosphere
50
____% of the atmosphere is composed of nitrogen gas
78% (the rest is in rocks n stuff)
51
______ process is bad for us/plants while ______ process is good for us/plants
denitrification; nitrogen fixation
52
while denitrification is bad for us, what is it good for?
waste-water treatment (removes N from waste)
53
2 steps of nitrification:
1) ammonia ---> nitrite (NO2-)
2) nitrite (NO2-) ----> nitrate (NO3-)
54
what organism completes the first step of nitrification where it transforms ammonia into nitrite?
Nitrosomonas
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what organism completes the second step of nitrification where it transforms nitrite into nitrate?
Nitrobacter
56
nitrification is a ______ process
oxidation
57
denitrification is a _____ process
reduction
58
plants can assimilate nitrogen from ______ or ______
ammonia or nitrate (NO3-)
59
plants prefer to assimilate _____ bc it is easier
nitrate (compared to ammonia)
60
can be easily leeched from soil and get into ground water
nitrate
61
nitrate in ground water can cause what disease?
blue baby syndrome
62
in blue baby syndrome, nitrate binds to _______ making it less able to carry oxygen
hemoglobin
63
the legume-root nodule is a plant-bacterial _______ type of symbiosis
mutualism
64
plants with seeds that grow in PODS (ex: soybeans, clover, alfalfa, beans, peas, and peanuts)
legumes
65
infection of legumes by nitrogen-fixing bacteria, known as _______, leads to the formation of root nodules
rhizobia
66
live in roots and take nitrogen gas from the atmosphere and fix it to ammonia; gives plants a source of Nitrogen; both benefit from it
rhizobia
67
bc of rhizobia, legumes can grow well in what type of soil?
nitrogen deficient soil
68
legumes play a key role in _____ _____
crop rotation (replenish soil with nitrogen)
69
_____ leaves = not getting enough nitrogen
yellow
70
T/F: plants NOT infected by rhizobia grow better
false
71
herbivorous mammals that posses a rumen
ruminants
72
examples of ruminant animals
cows, sheep, and goats (not horses)
73
digestive organ within which cellulose and other plant polysaccharides are digested by microbes
rumen
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order of food particles through a ruminant animal (5):
1) esophagus
2) reticulum
3) omasum
4) abomasum
5) small intestine
75
part of ruminant digestive tract: sorting room; sorts large and small particles (small can pass)
reticulum
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part of ruminant digestive tract: acidic stomach
abomasum
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part of ruminant digestive tract: moving organ; mixes plant material microbes in rumen digest plant material (cellulose to sugars) and the rest ferment sugars into volatile fatty acids which are absorbed into the bloodstream by the walls of this
rumen
78
main source of energy for ruminant animals comes from the _____
rumen (absorption through walls)
79
in the rumen, microbes digest cellulose into sugars and the rest ferment sugars into _____ ______ _____ which are absorbed into the bloodstream through the walls
volatile fatty acids
80
the reticulum sends small particles to the ______ and large particles to the ______
omasum; rumen
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what is not digested in the rumen is ________ so cows can continue to chew and break it down to smaller pieces
regurgitated
82
man-made hole in cow for scientific purposes
fistula (can stick your FIST in it)
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microbes in the rumen are mostly _______
anaerobes
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there are ____ to ______ microbes per gram of rumen contents
10^10 to 10^11 microbes
85
cellulolytic microbes hydrolyze ____ to free ______
cellulose to free sugars
86
fermentation of sugars in the rumen yields what 3 things?
- volatile fatty acids
- CO2
- CH4
87
pass through rumen wall into bloodstream; serve as the ruminant's MAIN energy source
volatile fatty acids
88
volatile fatty acids/fermentation products (3):
- acetate
- propionate
- butyrate
89
volatile fatty acids are produced in an ______ environment with a constant _____
anoxic; pH
90
microbial environments in nature are _____ and constantly _______
complex + constantly changing
91
microbial environment conditions are determined in part by ______ _____ of the community
metabolic activties
92
resources in microbial environments are highly _____ and often _______
variable; suboptimal
93
there is a "_____________" existence of resources for bacteria; doubling exponentially is actually RARE bc of this
"feast-or-famine"
94
microbes also have to deal with _______ substances when trying to acquire resources
inhibitory substances
95
microbial environments in nature have a ______ or ______ relationship
competition or cooperation
96
in a soil particle, each layer counts as a different _________
microenvironement
97
assemblages of bacterial cells attached to a surface
biofilm
98
biofilms are a ______ community
heterogenous
99
what makes biofilms a heterogenous community (2)?
- metabolic differences
- location
100
biofilms are enclosed in an _______ _______
adhesive matrix
101
adhesive matrix traps _____ for microbial growth and help prevent _____ of cells
nutrients; detachment
102
biofilms provide _____ for cells
protection
103
microbial interactions within biofilms (3):
- metabolic exchange
- DNA uptake
- quorum sensing
104
microbial interaction within biofilm: increases diversity; helps pick up advantageous genes
DNA uptake
105
quorum sensing is _____ dependent
density
