exam four (microbial ecology)

Question 1

same place, same species

Answer 1

population

Question 2

populations living together (multiple species in one area)

Answer 2

community

Question 3

what defines a niche (habitat)

Answer 3

location, nutrients available, what it interacts with

Question 4

the ___ and _____ govern microbial growth in nature

Answer 4

resources and conditions

Question 5

growth rate is variable because _____ of living are variable

Answer 5

conditions

Question 6

microbes can store energy using ____ ___

Answer 6

storage polymers (growth rate will decrease but can remain viable)

Question 7

involves transfer of electrons and play a key role in metabolic reactions

Answer 7

redox reactions

Question 8

microbes play a critical role in ____ _____

Answer 8

carbon cycling

Question 9

microbes create a _____; aggregation of microbes together (they love surfaces)

Answer 9

biofilm

Question 10

assemblages of bacterial cells attached to a surface and enclosed in an adhesive matrix

Answer 10

biofilm

Question 11

the matrix is protective because of (also nucleic acid and protein)

Answer 11

polysaccharide

Question 12

the biofilm develops upwards and has ____ ____

Answer 12

water channels

Question 13

the biofilm will get a signal and _____ will occur

Answer 13

dispersal

Question 14

what does the matrix protect microbes from

Answer 14

antimicrobials and biocides; grazing (by protozoans and immune system; means being consumed) and other stresses (such as temp.)

Question 15

the biofilm allows communication through

Answer 15

quorum senses

Question 16

in a biofilm there is ____ whether it is a population or community (become very formidable)

Answer 16

diversity

Question 17

three major places biofilms are found

Answer 17

environment, industrial and health

Question 18

very thick biofilms with different layers of microbes (each layer has its own requirements); they are all supporting eachother

Answer 18

microbial mats

Question 19

as you go deeper in biofilm ___ and ____ decrease

Answer 19

O2 and pH

Question 20

terrestrial environments for microbes

Answer 20

soil and terrestrial subsurface (enclosed grounwater)

Question 21

(soil layers) lots of organic matter and microbes

Answer 21

A horizon

Question 22

(soil layers) little organic matter and less microbes

Answer 22

B horizon

Question 23

(soil layers) undecomposed plants

Answer 23

O horizon

Question 24

soil surrounding plant roots; high microbial abundance

Answer 24

rhizophere

Question 25

soil is ____; many species which vary by soil type and geography;

Answer 25

complex

Question 26

majority of soil bacteria

Answer 26

actinobacteria, proteobacteria, bacteroidetes

Question 27

aquatic environments for microbes

Answer 27

freshwater and marine

Question 28

microbes living in lakes or streams; seasonal changes in temp., the microbes affect oxygen and carbon cycles (what environment?)

Answer 28

in freshwater environemtns

Question 29

input of sewage and other waste waters cause oxygen to rise; what happens?

Answer 29

bacteria increases and algae and cyanobacteria increase (overgrowth)

Question 30

microbes present in freshwater

Answer 30

proteobacteria. actinobacteria, bacteroidetes and cyanobacteria

Question 31

microbes live in more constant and cooler temp., low nutrient levels, results in fewer and smaller microbes

Answer 31

marine environment

Question 32

coastal areas have terrestrial runoff, are shallow and phototropic; what grows there

Answer 32

chlorophyll

Question 33

the marine environment has biological activity which uses up oxygen and demand exceeds availability (affects aerobes); this is called

Answer 33

oxygen minimum zone

Question 34

open ocean; prokaryotic or eukaryotic

Answer 34

phototrophs

Question 35

phototroph that is related to cyanobacteria and responsible for half the photosynthetic biomass (10^5 CFU/mL)

Answer 35

prochlorococcus

Question 36

bacteria in open ocean grows under low nutrient levels; small

Answer 36

pelagibacter

Question 37

there are 10x more ____ than cells in the open ocean

Answer 37

viruses

Question 38

low temp, high pressure, low nutrient and light environment (sediments and hydrothermal vents)

Answer 38

deep sea environment

Question 39

microbes present in deep sea

Answer 39

chemotrophs, piezophiles (high pressure), psychrophiles

Question 40

what microbes in hydrothermal vents

Answer 40

thermophiles and hyperthermophiles (bacteria and archaea)

Question 41

prolonged microbial interaction with other organisms

Answer 41

symbioses

Question 42

microorganism benefits, host harmed

Answer 42

parasitic symbioses

Question 43

one benefits , the other unharmed

Answer 43

commensal symbioses

Question 44

both species benefit from interaction

Answer 44

mutualistic symbioses

Question 45

a fungus (ascomycete) and phototroph (alga) are ____; the phototroph provides organic material and fungus provides anchor to grow

Answer 45

mutualism

Question 46

microbe attaches to root and gives plant more nutrients (legume; nitrogen fixing)

Answer 46

rhizobia

Question 47

agrobacterium and crown gall have a ____ symbioses

Answer 47

parasitic

Question 48

infect insects and is heritable, it scews the sex ratio in mosquito (makes male mosquitoes; lessens transmission of diseases)

Answer 48

wolbachia

Question 49

attine (leaf cutter) ants have a mutualism with fungus

Answer 49

the ant feeds the fungus and the fungus feeds the ant

Question 50

another fungus (escovopsis) destroys leaf garden and bacteria ____ is added to inhibit escovopsis

Answer 50

actinobacterium (pseudomonocardia)

Question 51

with the actinobacteria added to the leaf garden a _____ will grow to inhibit it

Answer 51

yeast

Question 52

rumen is the cow stomach and cellulose is digested then, what helps it break down

Answer 52

celluloytic microbes (they release glucose)

Question 53

the cud that is regurgitated is used by ____ for animal energy source

Answer 53

fermenters