Cell membrane is the answer
Answer:
la verdad no se perdón ame
<span>In liver, the most intensively studied transmembrane and intracellular signal transduction pathways are the Janus kinase signal transduction pathway, the mitogen-activated protein kinases signal transduction pathway, the transforming growth factor β signal transduction pathway, the tumor necrosis factor α signal transduction pathway and the recently discovered sphingolipid signal transduction pathway. All of them are activated by many different cytokines and growth factors. They regulate specific cell mechanisms such as hepatocytes proliferation, growth, differentiation, adhesion, apoptosis, and synthesis and degradation of the extracellular matrix. The replication cycle of hepatitis C virus (HCV) is intracellular and requires signal </span>
Carbonized remains are thin, approximately two-dimensional films of carbon preserved on a flat surface of rock. They are most often black in color, reflecting the fact that they composed mostly of carbon (as is coal, which is also black in color). Most fossils that exhibit “soft part” preservation are carbonizations.
I would say the answer is the Carbon remains of the original organism.