Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
As you stated before, cellulose is found throughout the cell walls of plant cells. Cellulose makes cell walls rigid, so that would indicate that cellulose is a carbohydrate.
<span>Nudation is the process wherein an ecological system experiences new growth after a major event. Given that a drought killed all of the plants in the farmland and the wind and birds moved new plants into the now barren area, this is an ecological succession.</span>
