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.
Definition of cellulose - an insoluble substance which is the main constituent of plant cell walls and of vegetable fibres such as cotton. It is a polysacch Definition of cellulose - an insoluble substance which is the main constituent of plant cell walls and of vegetable fibres such as cotton. It is a polysacch dictionary