evidence for evolution (fossils.)

Question 1

define fossil.

Answer 1

the remains of organisms from thousands of millions of years ago and found in rock.

Question 2

what can fossils help prove?

Answer 2

certain animals existed when and what they were like.

Question 3

how can fossils form?

Answer 3

layers of land pile on top and minerals go into the bones.

Question 4

why might some fossils be missing from records?

Answer 4

earth animals not discovered.
underground.
break away.
didn’t have bones.

Question 5

forming fossils: what are the three methods of making fossils?

Answer 5

preservation with no decay, gradual replacement by minerals, cats and impressions.

Question 6

forming fossils: what is the preservation with no decay method?

Answer 6

1 or more conditions required for decay not present. eg: little or no oxygen present, poisonous gas kills off bacteria causing decay, temperatures too cold.
animals preserved almost intact.

Question 7

forming fossils: what is the gradual replacement by minerals method?

Answer 7

harder parts of the animal/ plant are replaced by minerals and becomes art of the rock over long periods.
mould fossils formed when impression of an organism made in mud, becomes fossilised.

Question 8

forming fossils: what is the casts and impressions method?

Answer 8

can be formed when an organism is buried in soft soil like clay.
clay hardens and organisms decays.
things like footprints are pressed into soft materials.

Question 9

what can we learn from studying fossils?

Answer 9

age of layers of rock. difference and similarities of fossils in different habitats and evolve. suggest a habitat.

Question 10

what are the limitations of fossil records?

Answer 10

few organisms form fossils.
soft-bodied organisms completely decay.
can be damaged.
gap in records.