Models suggest that autotrophs
may be either enhanced by reduced herbivory or limited by increased herbivory, depending on whether the number of trophic levels is even or odd (Power 1992, Estes 1996).
This suggests that the primary determinant of the N:P of CNR is food N:P and that grazer body N:P is secondary, a reasonable conclusion given the likelihood that cellular elemental composition is considerably more variable (both intra- and interspecifically) for autotrophs
than for metazoans (Sterner and Hessen 1994).
In the course of studying biogenesis, we became aware of bacteria that were reductive autotrophs
and fixed carbon from carbon dioxide through the reductive tricarboxylic acid (rTCA) cycle (Fuchs, 1989).
, all the anabolic pathways begin in this cycle.
In the first experiment, we constructed aquatic, microbial microcosms containing small numbers of autotrophs
(unicellular green algae) and decomposers (heterotrophic bacteria) and maintained them under uniform environmental conditions for many ([greater than]25) generations, but randomly varied the number of consumer species (heterotrophic protists) stocked in these replicate microcosms.
The case is somewhat puzzling because what it means is that mixotrophy is so important in regulating the food web that the mixotroph must survive as an autotroph
This also resulted in significant differences in the average masses of trophically linked herbivore and autotroph
taxa for respective systems (Fig.
MA] is the specific velocity of growth of autotroph
Yet many believe that heterotrophs evolved before autotrophs
, which makes the autotroph
drooling even harden to justify.
New species VIDEO TRANSECTS Feeding Mode GH SH KWI BI Macroalgae Chlorophyceae Filamentous green autotroph
X algae Phaeophyceae Fucus sp.
Table 3-1 The Five Kingdom System Kingdom Cellular Nutrition Type Examples Organization Monera * Prokaryotic * Varies Bacteria * Unicellular Fungi * Eukaryotic * Heterotroph Molds, yeasts, * Unicellular or (cannot make mushrooms, multicellular its own food) smuts, rusts * Absorptive Protista * Eukaryotic * Heterotroph Protozoa * Unicellular (a few autotrophic species exist) Animalia * Eukaryotic * Heterotroph Invertebrates, * Multicellular * Ingestive vertebrates Plantae * Eukaryotic * Autotroph
Plants, mosses, * Multicellular (can make its ferns own food) Table 3-2 Classification of the House Cat, Human, and E.
A leafy liverwort (Porella pinnata) was the dominant autotroph
, both in terms of AFDM and N content, and covered 19.
Their hypothesis, in my view, suffers from the weakness that it requires a huge changeover in the metabolism of the host from an autotroph
[which makes ATP from nonorganic fuel] to a heterotroph [which generates energy from organic molecules]," he says.
Just as there are important economic differences between an autotroph
and a heterotroph, so, too, there are important economic differences between an organism that can think and one that cannot.
The plant on your windowsill is an autotroph
, and so are many of the microorganisms that live in the sunlit portion of the ocean.