Microbial Interactions

Question 1

Populations

Answer 1

assemblages of similar organisms

Question 2

Communities

Answer 2

mixtures of different populations

Question 3

Ecosystems

Answer 3

self-regulating biological communities and their physical environment

Question 4

Symbioses

Answer 4

relationships among organisms in an ecosystem

Question 5

Ectosymbiont

Answer 5

located on the surface of another larger organism

Question 6

Consortium

Answer 6

physical contact between different organisms of similar size
biofilm

Question 7

Endosymbiont

Answer 7

located within another organism

Question 8

Ecto/endosymbiosis

Answer 8

lives both inside and outside of another organism

Question 9

Mutualism

Answer 9

• two organisms that cannot live without one another
• Metabolically dependent on each other
  Buchnera aphidicola and aphids
  Rumen microbes and Ruminants

Question 10

Cooperation

Answer 10

• both organisms benefit from living with each other but can also exist apart from each other
• syntrophism
• Chromatium provides organic matter and Desulfovibrio provides CO2 and H2S

Question 11

Syntrophism

Answer 11

growth of one organism depends on or is improved by growth factors or nutrients from another organism growing nearby

Question 12

Commensalism

Answer 12

• one organism benefits and the other is neither harmed nor helped
• can also be syntrophic
• Nitrosomonas and Nitrobacter
• E.coli and Bacteriodes

Question 13

Predation

Answer 13

• one organism gains and the other is harmed
• predator engulfs or attacks the prey
• some protists, bacteria, fungi

Question 14

Parasitism

Answer 14

• one organism gains (parasite) and the other is harmed (host)
• slower process than predation
• viruses, fungi, lichens

Question 15

Amensalism

Answer 15

• negative impact of one organism on another based on release of a specific compounds
• antibiotics by bacteria and fungi
• bacteriocins
• organic acids during fermentation

Question 16

Competition

Answer 16

two organisms try to acquire or use the same resource
- one dominates and prevents the other from getting the substrate
- two share the resource, and both survive at lower population levels

Question 17

Microbes role in ecosystem

Answer 17

• primary producer
• decomposer
• impact plant function
• food for other organisms
• change amount of minerals in soluble and gas form