21. Picoeukaryotes can be either autotrophic and heterotrophic, and usually contain a minimal number of organelles. 22. Microrganisms present are heterotrophic and autotrophic . 23. Many authorities who find it impossible are clearly citing sources for complex autotrophic self-replicating systems. 24. This pathway is also used for carbon fixation by autotrophic sulfate-reducing bacteria and hydrogenotrophic methanogens. 25. Ferric iron ( ) is a widespread anaerobic terminal electron acceptor both for autotrophic and heterotrophic organisms. 26. They are termed autotrophic because of their carbon source and termed aerobes because of their aerobic environment. 27. The plants are herbs, partially autotrophic ( photosynthetic ) but also partially parasitic on soil fungi. 28. Heterotrophic microorganisms are important in oxidising carbon ( decomposition ) whereas autotrophic microorganisms are important in nitrification. 29. In general, since these systems are autotrophic , they are the most difficult and complex known replicators. 30. These systems are substantially simpler than autotrophic systems, because they are provided with purified feedstocks and energy.
