1A. Soil Populations (cont'd)

Question 1

What is a limiting nutrient?

Answer 1

A nutrient required for the growth of an organism, but available in a lower quality than other nutrients.

Question 2

What is an anaerobe?

Answer 2

Bacterium that thrives in the absence of oxygen

Question 3

What is a microaerophile?

Answer 3

Bacterium that requires a small amt. of oxygen for growth

Question 4

What is an aerobe?

Answer 4

Bacterium that thrives in the presence of oxygen

Question 5

What is a soil micronutrient?

Answer 5

Mineral used in small quantities by plants

Question 6

What are symbioses?

Answer 6

“Cooperative” interactions b/w species

Question 7

What are antagonisms?

Answer 7

“Adversarial” interactions b/w species

Question 8

What is commensalism?

Answer 8

Relationship in which one species benefits from the ordinary actions/activities of the other

Question 9

What is synergism?

Answer 9

Two or more species acting together to create a result that none could achieve individually; non-obligatory relationship

Question 10

What is mutualism?

Answer 10

Highly specific, often obligatory synergistic relationship

Question 11

What is amensalism?

Answer 11

One species produces a substance that inhibits/kills one/more other species

Question 12

What is competition?

Answer 12

One or more species utilize the same resource; resource is limiting to all competing species

Question 13

What is parasitism?

Answer 13

One species benefits through the exploitation of the other

Question 14

What is predation?

Answer 14

One species uses another as a food source (predator = consumer)

Question 15

What is nutrient cycling?

Answer 15

A set of processes where organisms extract minerals necessary for growth from the soil or water, before passing them on through the food chain - and ultimately back to the soil + water.

Question 16

What is a facultative anaerobe?
Why are they important?

Answer 16

Any organism that can grow with or w/o free oxygen.

They can change their metabolic processes depending on the presence of oxygen, using cellular respiration (in presence of O2) + fermentation (in absence of O2)

Question 17

What is enrichment isolation? How can it be accomplished?

Answer 17

The use of certain growth media to favor the growth of a particular microorganism over the others, enriching a sample for the microorganism of interest.

• Its isolation in pure culture can be accomplished in various ways, such as dilution and plate cultures.