The main description of lithogenous came from rocks - Produced
as surface rock is broken down by weathering like wind, rain, freezing/thawing.
It is transported to the oceans by water, wind and gravity much sediment
remains on continental margins. However, some sediment ends up on deep ocean
floor as fine rock powder called red clay, brown clay, or brown mud. While Biogenous
came from remains of living organisms shell and coral fragments. Hard skeletal parts of single-cell organisms
of either calcareous (soluble shell) material or siliceous (non-soluble, clear,
hard) material.
Operons afford the organism the opportunity to
simultaneously regulate transcription of multiple genes, whose products are
active in the same process. Operons lead to the synthesis of groups of functionally
related enzymes, usually from a single mRNA transcript hence makes regulation of
the genes highly efficient.
