1. How are fossils formed? Write in brief.
2. Due to natural disasters such as volcanoes, floods and earthquakes, dead plants and animals get buried under the surface of the earth. Then, the delicate and soft parts of plants and animals decay while the hard parts remain in the soil. The process of pressing down of these parts by the soil above them continued in the ground for a very long time and finally, the external morphology of these hard parts is formed on the soil which by then have changed into sedimentary rock. In this way, fossils are formed.
3. Why is fossil found only in sedimentary rock?
4. Fossils are found only in sedimentary rock because fossils are formed in rocks by dead bodies. The things which cover the dead bodies change into the sedimentary rock in which fossils are preserved.
5. Write any two difference between Mesozoic era and Cenozoic era.
6. Two difference between Mesozoic era and Cenozoic era are shown below in table:

   Mesozoic era	Cenozoic era
   This era began 250 million years ago and ended some 65 million years ago.	This era began 65 million years ago and still going on.
   This era was dominated by giant reptiles like dinosaurs.	Human dominance began in this era.

7. Why did dinosaurs evolve earlier than human?
8. Dinosaurs evolve earlier than humans because during the Mesozoic era lands were swampy, the temperature was high than that of now which was favourable for the development of dinosaurs but humans could not survive in that environment.
9. Why fossils are not found in igneous rock?
10. Fossils will not be present in igneous rocks as they are formed from molten material and obviously, magma and lava can't contain any life forms.
11. Write any two information obtained by the study of fossil.
12. Information obtained by the study of fossil are:
    1. We can know the evolutionary development of living beings.
    2. We can know the deposits of coal and petroleum.
    3. We can know the ancient condition and climate of the earth.
13. What is the evidence that there were dinosaurs on the earth in the past history?
14. The evidence that there were dinosaurs on the earth in the past history is their fossils. Paleontologists look for clues preserved in ancient rocks: the fossilized bones, teeth, eggs, footprints, teeth marks, leaves, and even dung of dinosaurs.
15. Write any two importance of fossil.
16. Any two importance of fossil are:
    1. We can know the deposits of coal and petroleum.
    2. We can know the ancient condition and climate of the earth.