1. What is an ecosystem? Give an example. 2. What are examples of abiotic and biotic factors?

3. Why are both biotic and abiotic features important in ecosystems and biomes?

4. What is the difference between ecosystems and biomes?

5. How do the biotic factors vary within an ecosystem and why?

6. List the levels of organization within environments. (Community, species, habitat, ecosystem, population)

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.

they have identical fossils of organisms that have evolved over time.

both have animal fossils preserved in them due to weathering and erosion.

they contain different fossils because life on earth has changed through time.

the fossils in them were formed on the surface of earth due to exposure to sunlight.