Fossils

Which part of an organism is preserved in cast and mold fossils?

• skin

• bone

• muscle

• soft tissue

Which correctly lists three materials that preserve soft tissues in fossils?

• amber, minerals, and sediment

• minerals, permafrost, and amber

• permafrost, amber, and tar

• sediment, minerals, and amber

Why is still water an ideal environment for the formation of mold and cast fossils?

• sediment builds up over organisms

• sediment turns organisms into rock

• hard tissue decays under sediment

• soft tissue is preserved under sediment

How do organisms form carbon films?

• organisms turn into rock

• residue is left on rocks when organisms decay

• hollow forms are left in sediment by decaying organisms

• organisms leave evidence of their activities such as footprints

What happens to soft parts of organisms when cast fossils form?

• they decay

• they petrify

• they form carbon films

• they become part of the fossil

How are casts formed by decaying organisms?

• organisms turn into rock over time

• organisms leave carbon residue on a rock

• organisms leave impressions in sediment that hardens into rock

• impressions left by organisms are filled in with sediment that hardens into rock

Which type of fossils form from hardening sediment?

• casts

• tar pit fossils

• carbon films

• amber fossils

Which feature do amber fossils have that mold fossils do not?

• preserved soft tissue

• organisms turned into rock

• solid copies of the original organism

• impressions of hard tissues left by organisms

Study the image. How does this fossil differ from fossils that have preserved remains? Which feature does this fossil have that preserved remains do not have?

• it has carbon residue left by a decaying organism

• it was formed from tree sap that turned into amber

• it was preserved in frozen soil called permafrost

• it includes the preserved soft tissue of an organism

The image shows a fossil that is hard like rock but that resembles a tree. Which statement explains how this type of fossil differs from a trace fossil?

• this fossil reveals the activities of an organism

• this fossil was created in solidifying sediment

• this fossil is an impression left by an organism

• this fossil was an organism that has been turned into rock