Lecture 37 - Environmental Nutrient Cycles

Question 1

Describe relationships between producers, consumers, and decomposers

Answer 1

Producer = autotroph
Consumer = heterotroph
Decomposer = heterotroph but specializes in decomposition

Question 2

What are the two sources of energy input for an ecosystem?

Answer 2

Radiant energy and chemical energy

Question 3

What adaptation required for oligotrophic environments?

Answer 3

I. Growth rate very slow
II. efficient transporters to concentrate nutrients

Question 4

What adaptation required for environments crowded with other organisms?

Answer 4

I. produce bacteriocins
II. produce quormones/anti-quormones

Question 5

What adaptation required for environments with rapidly flowing water?

Answer 5

I. aerobes and phototrophs
II. “super” biofilm

Question 6

What adaptation required for soil environments?

Answer 6

I. form microcolonies

Question 7

Example of microbial succession

Answer 7

fermentation in dairy products and sauerkraut

Question 8

Is CO2 to glucose oxidation or reduction?

Answer 8

Reduction

Question 9

Which steps in the carbon cycle require energy input?

Answer 9

Photosynthesis requires radiant energy

Question 10

_______ bacteria produced glucose from CO2

Answer 10

Autotrophic

Question 11

__________ oxidize glucose to CO2

Answer 11

Heterotophs

Question 12

_____________ reduces atmospheric N2 to NH4

Answer 12

Nitrogen fixation

Question 13

Dissimilatory vs assimilatory nitrogen fixation

Answer 13

dissimilatory: chemical ammonia is major product
assimilatory: reduced nitrogen is incorporated into biomass

Question 14

__________ oxidizes NH4 to NO2/NO3

Answer 14

Nitrification

Question 15

__________ reduces NO3 to N2

Answer 15

denitrification

Question 16

________ oxidizes NH4 and reduces NO2 to N2 anaerobically

Answer 16

anammox

Question 17

Photosynthetic sulfur bacteria vs sulfur oxidizing bacteria

Answer 17

PSB: oxidize H2S (or S) to SO4 (or S)
SOB: oxidize H2S (or S) to SO4

Question 18

Sulfate reducing bacteria

Answer 18

SO4 reduced to H2S

Question 19

What are the basics of how fixed nitrogen is incorporated into plant tissues?

Answer 19

Bacteroids turn into root nodules on legume roots

Question 20

How do biogeochemical cycles occur in the deep ocean without solar energy input?

Answer 20

thermal vents release hydrogen sulfide (H2S) which is used as an electron source

Question 21

Name 2 ways in which symbiotic fungal associations can increase plant root surface area

Answer 21

wrap around outside of plant root cells
live inside plant root cells

Question 22

Describe a lichen (looks and composition)

Answer 22

fungal filament which acts like a root
it get nutrients from photosynthetic partner