Klausurfragen Flashcards
Why is the center of an aggregate anaerobic?
- microorganisms that are within the aggregate use up the oxygen in the center
- the oxygen on the outside is being replenished just as fast as its being used up
- Tortuosity of the pores (oxygen cant get in fast enough)
- diffusion slow
Externe validiität
The degree to which your results can be generalised
bezeichnet die Generalisierbarkeit des Zusammenhangs zwischen unabhängiger und abhängiger Variablen auf natürliche Situationen
was ist das am meisten verbreitete experimentelles design?
Faktorielles design (2 faktoren) komplettes faktorielles experiment ->all factors are combined with each other
Definition of Fungi
Fungi are defined as organisms that are:
eukaryotes, heterotrophic and have absorptive nutrition;
that reproduce by means of spores and typically produce a hyphal body (mycelium).
fungi as tunneling machines
filament grows from the tip, otherwise it would have to be very rigid to avoid buckling.
Exerts hydrostatic pressure
Produces hydrophobins which are protiens that attach to surrounding so that force can be exacted (bracing)
Plant soil feedback (Bever 2002)
.
what is soil?
A natural body, synthesized in profile form from a variable mixture of broken and weathered minerals and decaying organic matter, which covers the earth in a thin layer and which supplies, when containing the proper amounts of air and water, mechanical support and, in part, sustenance for plants
…with its living organisms…
Causality
The importance of experimental design stems from the quest for inference about causes or relationships as opposed to simply description.
observational studies dont give causalities
randomization
which experimental unit recieves which treatments must be randomised
position must be randomised
best to keep treatments blind
What is the definition of experimental unit?
what the treatment is being applied to, should be same as replica
e.g. Petri dish, flask, microcosms, growth chamber, pot
How can you investigate a trophic chain? (food web description)
- stomach content analysis
- feeding trials (what eats what)(only cultured representatives)
- direct observation
- label with C13 or N15
What is the problem with measuring exudates (in general) and - how can they even “work”?
theory 1. time lag in excretion of root exudates and arrival of microorganisms who “eat”/ decompose exudates (this also leads to spatial separation of initial excretion of exudates and microorganisms)
theory 2. transport of substances via a mycorrhizal fast lane
What qualifies a global driver of global change?
- Weltweite Verbreitung
- exponentielle Veränderungen in Bezug auf Bevölkerung und Wirtschaftswachstum
- bekannte Auswirkungen auf Organismen
Which two steps are needed for feedback? Which disadvantages is Bever facing because of the “single genotypes?”
- training phase
- conditioning phase
What is “heterotrophy”, “autotroph”, “chemotroph”, “prototroph”, “lithotroph”, “and organotroph”?
heterotrophs- need organic CARBON
autotrophs- use CO2 as CARBON source
chemotrophs- use chemical compounds as ENERGY source
phototrophs- use light as ENERGY source
lithotrophs- use inorganic substances as ELECTRON DONOR
organotrophs- use organic substances as ELECTRON DONOR
