Intro Flashcards
Why study nutrient cycling + prokaryotes?
studying prokaryotes allows us to classify organisms at a fundamental level and provide an understanding of life that evolved prior to organisms with nuclei
What was Carl Woese’s main discovery when he studied 16s rRNA?
He determined that prokaryotes are not monophyletic as was previously thought, but instead, exist as 2 different groups with different sequences of nucleic acids and rRNA
(EU) bacteria and (Archae) bacteria = bacteria and archaea
What environments do Archaea typically live in?
extreme environments typically with high sulphur content
What are the points of view that biological systems can be defined by?
community structure
trophic dynamic levels (population)
energy transfer and nutrient cycling
Describe how community structure can be used as a point of view to describe complex biological systems
the system is defined by the primary producers and the plant community (ex. trees)
Describe how trophic dynamic levels (population) can be used as a point of view to describe complex biological systems
the system is defined by the animal populations and their interactions
Describe how energy transfer and nutrient cycling can be used as a point of view to describe complex biological systems
the system is defined by the prokaryotes that function and have functioned in the past
Why is studying prokaryotes important for understanding eukaryotes?
the current paradigm is that eukaryotic cells evolved from a symbiosis of prokaryotic cells billions of years ago that retained their ancestral rRNA
What key nutrients do bacteria and archaea play an essential role in transforming? How?
organic carbon, nitrogen, sulfur
they are key regulators of ecosystem productivity
How are trophic interactions linked to nutrient cycling?
primary producers produce different phytochemicals which influence trophic interactions and ecosystem nutrient dynamics (ex. lignin, cellulose, tannins, terpenes)
the phytochemicals will influence the herbivorous populations which will influence the carnivorous populations and the herbivorous community will limit the type of and abundance of plants
the phytochemicals will influence the nutrient dynamics which in turn will influence which plants grow and how well they grow
there’s 3 feedback loops:
- between the phytochemicals produced by plants and trophic interactions
- between the phytochemicals produced by plants and ecosystem nutrient dynamics
- between trophic interactions an ecosystem nutrient dynamics which includes the other 2 loops
How are spatial and temporal variations linked by feedback loops?
there’s different layers on the phytochemical landscape (ie., the way the phytochemicals influence other aspects of the ecosystem) which include:
nutrient availability
phytochemistry
herbivore activity
predation pressure
What kind of qualitative and quantitative methods are needed to develop and provide evidence for the spatial and temporal links to the feedback loops on the phytochemical landscape?
- observation and identification of members of the ecosystem (plants, animals, bacteria)
- quantitative data collection
- field sampling and statistical analysis using bio, chemical, and physical methods
- uni- and multivariate
- correlation/regression - experimenting in the lab and in the field
- statistical theory of decision
- use random block design
- mathematical distribution (ex., Guassian, Lognormal, Poisson)
What are the practical reasons for studying nutrient cycling + prokaryotes?
agricultural reasons:
- N2 fixation
- nutrient cycling
- animal husbandry
- gut bacteria in the animal gut microbiome
food industry:
- food preservation (heat, cold, radiation, chemicals)
- fermented foods
- food additives (monosodium glutamate, citric acid, yeast)
disease:
- identifying new diseases
- treatments, cures, and prevention`
energy/environmental reasons:
- biofuels
- fermentation
- bioremediation
- microbial mining
biotechnology:
- GMOs
- pharmaceuticals (ex. insulin)
- gene therapy
Where are prokaryotes?
everywhere! in all biomes
What are biomes?
a biogeographical unit within which a biological community exists in response to a similar regional climate
ex. temperate rainforest, steppe, grassland
Who was the first to establish the major biogeoclimatic zones in BC?
Krajina
How can the communities within a biome vary? explain why
multiple communities, aside from the dominant one, can develop on specific habitats within a biome and this can include different plants and bacteria
this occurs because:
- water moisture levels can vary depending on the slope (low at the top of the slope, high at the bottom of the slope = different habitats
define xeric
when moisture levels are low
define hydric
when moisture levels are high
Explain how Mt Doug is a good representation of multiple communities existing in different habitats related to elevation gradient
there are 3 communities on Mt Doug
at the bottom, where moisture levels are high and nutrients are abundant: Western Red Cedar dominates
in the middle, where moisture and nutrient levels are intermediate: Douglas-fir dominates
at the top, where moisture levels and nutrient levels are low: Garry Oak dominates
What conditions do Douglas-fir grow best in?
high nitrate (NO3-) rather than ammonia (NH4+)
What did Krajini suggest as an explanation for how Douglas-fir has come to dominate the forest ecosystem on Mt Doug? What other factor is being considered now as well?
nitrification of ammonia to nitrate
now being more considered is the role of mycorrhiza
What is the scientific name for Douglas-fir?
Pseudotsuga menziesii
What is the scientific name for Western Red Cedar?
Thuja plicata