Evolution of photosynthesis symbiotic relationship with chloroplasts they capture from the algae in their diet and then store in their bodies. This allows the mollusks to survive solely by photosynthesis for several months at a time. Some of the genes from the plant cell nucleus have even been transferred to the slugs, so that the chloroplasts can be supplied with proteins that they need to survive. An even closer form of symbiosis may explain the origin of chloroplasts. Chloroplasts have many similarities with photosynthetic bacteria, including a circular chromosome, prokaryotic-type ribosomes, and similar proteins in the photosynthetic reaction center. The endosymbiotic theory suggests
Microbiologically induced calcite precipitation autotrophic production of carbonate obtain carbon from gaseous or dissolved carbon dioxide. These pathways include non-methylotrophic methanogenesis, anoxygenic photosynthesis, and oxygenic photosynthesis. Non-methylotrophic methanogegenesis is carried out by methanogenic archaebacteria, which use CO and H in anaerobiosis to give CH. Two separate and often concurrent heterotrophic pathways that lead to calcium carbonate precipitation may occur, including active and passive carbonatogenesis. During active carbonatogenesis, the carbonate particles are produced by ionic exchanges through the cell membrane by activation of calcium and/or magnesium ionic pumps or channels, probably coupled with carbonate ion production. During passive carbonatogenesis, two metabolic cycles can be involved,