Populations and Life Strategies Flashcards

Question

What is the response to enrichment to r-strategists

Answer 1

Fast growth after variable lag

Answer 2

Slow growth after variable lag

Answer 3

Often catastrophic

Answer 4

Dominant regulator of population density is predation - it doesn't have to be a large predator but it can be a disease or anything else that can kill you

Answer 5

Dominant regulator of population density is nutrient availability

Answer 6

If grazing pressure exceeds bacterial productivity, we will find ourselves in a top-down control attempt to get a stable community - defense specialists will dominate

Answer 7

If bacterial productivity exceeds grazing pressure, we will find ourselves in a bottom-up control to attempt to get a stable community - competition specialists will dominate.

Answer 8

Total biomass of any organism determined by the nutrient present in lowest concentration relative to the requirements of that organism.

Answer 9

There are bounds for environmental factors above and below which microorganisms cannot grow

Answer 10

Source of phosphorus is erosion from rocks - there is no biological mechanism to pull phosphorus out of the atmosphere

Answer 11

Source of nitrogen is nitrogen fixation - nitrogen-fixing bacteria/lightning we can't incorporate it into it has been fixed into ammonia or nitrite

Answer 12

Source of carbon is atmosphere - CO2 is being fixed by plankton/algae into carbon

Answer 13

If we were to add free iron to high nitrate area in the ocean can lead to fertilization. Fertilization with iron would lead to large blooms, which would then sink, removing carbon dioxide from the atmosphere.

Answer 14

Complex trophic interactions prevent this - many studies show no carbon sequestration. Initially there was positive results, but within a few days all that biomass was returned to the atmosphere.

Answer 15

1. Prey and Predator are both increasing in populations 2. Predator increasing it leads to prey decreasing 3. Prey decreasing leads to predator decreasing 4. Predator decreasing leads to prey increasing This continues in a cycle

Answer 16

They are free-living like plankton or surface attached like biofilm. Most bacteria that live in the environment are surface attached. Most lab studies focus on planktonic bacteria.

Answer 17

To isolate bacteria, we enrich (liquid), select colony (surface), and then do genetics and physiology with a combination of liquid and surface techniques. Liquid only isolation techniques have been used to isolate abundant, but previously uncharacterized, planktonic bacteria

Answer 18

Planktonic cells are in a more homogenous environment. Common in aquatic systems like lakes and oceans. This includes zooplankton, phytoplankton, bacterioplankton, and virioplankton. Even in the water column, most bacteria lived attached to particles.

Answer 19

Biofilm cells produce their heterogeneous environment with many micro-niches. Biofilms are collections of microorganisms surrounded by the slime (extracellular polymeric substances, EPS), they secrete, attached to an inert or living surface. Bacteria in the environment predominantly live in biofilms.

Answer 20

1. Reversible adsorption of bacteria - occurs in seconds 2. Irreversible attachment of bacteria - occurs in seconds to minutes 3. Growth and division of bacteria - occurs in hours to days 4. Exopolymer production and biofilm formation - occurs in hours to days 5. Attachment of other organisms to biofilm - occurs in days to months

Answer 21

``` Cell Membrane Cell Wall Structures Intracellular Materials Flagellum Extracellular Polymetric Material ```

Answer 22

1. Nutrients (macromolecules) collect at surfaces - source of food 2. Protection from environment 3. Physical proximity - allows easy exchange of products and assists with syntrophy and other forms of co-degradation 4. Genetic exchange (horizontal gene transfer)

Answer 23

Health risks and cosmetic degradation

Answer 24

Health risks and corrosion

Answer 25

Contamination

Answer 26

Caries and gingivitis

Answer 27

Increased drag and corrosion

Answer 28

Slowing draining sinks

Answer 29

Chronic infections

Answer 30

Pass through biofilter to degrade matter

Answer 31

Microbes are taking electrons from the surface of the material to the outside of the biofilm and dumping them on oxygen which causes a pit to form in the metal. Biocorrosion caused by bacteria results in pitting, crevice corrosion cracking. Fix with electroplating new metal onto the cracks.

Answer 32

Thick biofilms that are some of the earliest microbial fossils. Mainly found in extreme environments

Answer 33

The causative agent for human intestinal disease cholera. It is a burden to mainly underdeveloped countries which cannot afford to establish or to maintain necessary hygienic and medical facilities. Can be isolated and estuarine and aquatic environments. Survival in the relatively harsh environment is believed to be due to its ability to form a biofilm with zooplankton or egg masses.

Answer 34

Life history strategies represent a set of traits that tend to correlate due to physiological or evolutionary trade-offs, with different strategies favoured under different environmental conditions.

Answer 35

Grime's C-S-R triangle is an alternative framework that enumerates three major plant life history strategies: competitors (C) excel at maximising resource capture in productive and undisturbed systems, stress tolerators (S) prevail at continuously low-resource and stressful conditions, and ruderals (R) occupy recently disturbed but less stressful habitats

Answer 36

High yield strategists maximise the fraction of resource uptake that is allocated to biosynthetic processes by investing in central metabolism and associated assimilatory pathways such as amino acid, nucleotide, and fatty acid synthesis to build cellular components using these precursor components. The absence of resource limitation and stress are expected to favour the high yield strategy.

Answer 37

Resource acquistion by heterotrophic microbes depends on uptake of depolymerized substrates using various membrane transporters. It is probably that investment in resource acquisition traits is higher in resource abundant environments like the rhizosphere, we propose that this strategy will prevail in low-resource conditions where microbes would be under selection to increase resource capture at the expense of growth yield

Answer 38

Certain global patterns in phenotypic expression are common, including factors or molecular chaperons aimed to minimise or mitigate biomolecular damage. Thus, microbes exposed to suboptimal conditions would posses traits linked to stress tolerance at the expense of other traits.

Answer 39

Yield is often measured as the proportion of carbon substrate invested into biomass relative to that lost through respiration

Answer 40

Resource acquisition traits have been estimated with omics and biochemical techniques at both the population and the community levels

Answer 41

Stress tolerance taits in the form of factors, molecular chaperons, or specific physiological adaptations can be extracted from widely used omics tools.

Answer 42

Y-strategists with increased investment into growth and biomass production would contribute to microbial residue formation that can be stabilized through organo-mineral interactions or aggregation

Answer 43

A-strategists should contribute more to decomposition and carbon loss through investment in extracellular enzyme production. Selection for A-strategists could also occur under a lower organic matter environment that stimulates enzyme production to mine resources.

Answer 44

S-strategists might depend on the type of stress compounds produced, by diverting investment away from growth, S-strategists could also reduce soil carbon accumulation.

Populations and Life Strategies Flashcards

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