What can be learned by studying fossils (think in terms of ecology, what role does the environment play in the evolution of species)?

By studying fossils one can understand how long life has existed on earth.

The relation between the different types of plants and animals. How are they ancestrally related to each other.

Environment plays a huge role in preserving the fossils which can be used to know the information about the plants and animals.

It can also be used to know the environment which was found at that time. It can easily tell about the past time, the environment and everything about the past time.

answer; aerobic conditions; citric acid cycle (krebs cycle) electron transport chain;         anaerobic conditions; fermentation; both glycolysis;