Examples of index fossils. Index fossils (also known as guide fossils, indicator fossils or zone fossils) are fossils used to define and identify geologic periods (or faunal stages).
Methyl cellulose. Methyl cellulose (or methylcellulose) is a chemical compound derived from cellulose. It is a hydrophilic white powder in pure form and dissolves in cold (but not in hot) water, forming a clear viscous solution or gel.
Basically Cellulose is a polysaccharide (polymer) of Î²-Glucose monomers (molecules). Cellulose is a component of plant cell wall. It is the most abundant polymer on the surface of Earth.