Chapter Questions
Why do obligate mutualisms appear to be a more important type of interaction in coral reefs than in the benthos of lakes and streams?
How might shredders and scrapers alter microbial activity on leaves in streams?
Is it possible that interactions among organisms can change over time or with changes in biotic conditions?
Why is it less likely that individual diatom species found in periphyton assemblages would produce chemicals to deter scrapers than would macrophytes?
Planktonic bacterial populations may respond in a complex manner to temperature. Can you predict if lower growth or decreases in predation rates related to increased viscosity should be more important controls of biomass?
What kind of predator was the precursor to eukaryotic cells (before chloroplasts and mitochondria)?
Why is chemical sensing of microbial prey so important but visual identification more likely with larger scale prey?
Under what conditions might an algal species exhibit photophobic response? Why may an obligate anaerobe be photophobic?
Adhesion to collecting appendages may be an important mode of collection of bacterial prey. Why are viscous forces and Reynolds number important to consider in such cases?
Why are filter feeders found in the water column of lakes but mainly on the benthos (not as much in the water column) of rivers?