ENV MICRO

Question 1

Symbiosis

Answer 1

Two taxonomically unrelated species exist in intimate association with another

• Mutualism
• Commensilism
• Parasitism

Question 2

Mutualism

Answer 2

A relationship from which both partner species derive clear benefit…has two subtypes obligate and facultative

Question 3

Commensilism

Answer 3

A relationship from which one symbiont benefits at neither cost nor benefit to the second symbiont

Question 4

Parasitism

Answer 4

A relationship from which one species benefits at cost to individual host

Question 5

is parasitism costly to host species?

Answer 5

No because it takes care of the weak and ultimately strengthens herd immunity

Question 6

Facultative Mutualism

Answer 6

Humans harbor Staphylococcus species on skin epidermis. Humans benefit by gaining protection from pathogen. Symbiont gains place to live and derives nutrients from epithelial surface. May be any of several staphyloccocus species

Question 7

Obligate Mutualism

Answer 7

Warm blooded animals harbor E coli as large intestinal indegnous flora. We get protection against pathogens and vitamin K, they get warmth, humidity and nutrients

Question 8

Obligate Mutualism examples

Answer 8

• Leaf cutter ants & fungal gardens
• coral polyps & Anemones and zooxanthellae
• lichens

Question 9

Commensilism

Answer 9

diptheroids may colonize conjunctive they gain protected environment at neither cost nor benefit to the colonized animal

Question 10

Parasitism

Answer 10

an organism that cannot complete its life cycle without depending on a host in or on whose body it lives, and from whose tissues it derives metabolic support

-Viruses, Chlamydiae, Malaria, Toxoplasma gondii, and Diphyllobothrium latum

Question 11

Biofilms

Answer 11

• Microbes exist in communities within which there is quorum sensing
• communication that enables the members of the community to coordinate activities even though they are unicellular organisms
• hydrogel which contains abundant water and polysaccharides, dna and proteins along with cells
• communities may include only one species or diverse organisms

Question 12

Where do biofilms form and what can they do?

Answer 12

Bio films generally form on surfaces, plaque on teeth, filtering beds in sewage treatment plants, and indwelling medical devices

Organisms in biofilms do things individual cells would have a hard time doing on their own like in nutrient sharing, resistance to dessication and microbicides.

Question 13

Ecological Roles of Microbes

Answer 13

Microorganisms occupy virtually all potential types of niches…Producers, Detritivores, and Predaceous consumers

Question 14

Producers

Answer 14

Photoautotrophs: cyanobacteria, diatom, dinoflagellates

chemoautotrophs: many archaea

Question 15

Detritivores

Answer 15

Organisms of decay in soils and water

i.e slime molds, water molds, true fungi and many bacteria

Question 16

Predaceous consumers

Answer 16

Protozoans: Parmecium, Amoeba

Question 17

Biogeochemical Cycles

Answer 17

• Global scale cycles of biologically important elements or small molecules
• these cycles exist for Carbon, Nitrogen, Phosphorus, and Sulfer, some other elements and food and water
• cycle feature passage of material being cycled through four major reservoirs

Question 18

4 major reservoirs in biogeochemical cycles

Answer 18

• Atmosphere: air, including water vapor
• hydrosphere: liquid water on earth’s surface
• Lithosphere: solid, non living matter, crust, glaciers, etc
• Biosphere: living matter present in all ecosystems

Question 19

Microorganisms in biogeochemical cycles

Answer 19

• microbes mediate many steps in various biogeochemical cycles
• the major biogeochemical cycles could not be completed without the presence and activities of microorganisms

-in nitrogen cycle, certain steps in cycle are only done by microbes
-Nitrogen fixation is only done by a limited
variety of bacterial gene

Question 20

Carbon Cycle

Answer 20

Carbon fixation is the conversion of inorganic carbon usually as CO2 to organic carbon

 - most commonly done by photosynthesis
- done by plants and other photoautotrops such as diatoms and dinoflagellates

Question 21

diatoms

Answer 21

most abundant marine producers

Question 22

dinoflagellates

Answer 22

along with diatoms, these organisms are important as zooxanthellae symbionts of coral and anemones