Fossils And Ancient Life

Question 1

Fossils can be

Answer 1

Partial or complete remains
Have skin or hair
Bacteria or pollen
Footprint

Question 2

How fossils form

Answer 2

Sedimentary rock must be present 
Heat, rain , wind or cold exposure
Carried by rivers and settle down at the bottom 
Sediment layers build up 
No oxygen

Question 3

Paleontologists can reveal

Answer 3

Similarities and differences in bones today and long ago

What they environment could have been like

Question 4

Relative dating

Answer 4

Age of the fossil is determined by comparing its placement in the sedimentary rock with that of other fossils in other laters
Only an estimate of the age

Question 5

Index fossils

Answer 5

Fossils of a species that at easily recognized
Existed for a short period of time so will be found in a few layers of rock
Wide geographic distribution

Question 6

Radioactive or radiometric dating

Answer 6

Scientists can calculate absolute ages of the fossil based on the proportion of radioactive isotope to stable isotopes

Question 7

Fossil record

Answer 7

The fossil record provides evidence about the history of life that existed in earth

Question 8

Half life

Answer 8

The length of time it takes for half a sample of radioactive isotope to decay