AP BIOLOGY

Detailed explanation-1: -A copy of an organism preserved in the rock is called as cast fossil. Explanation: Cast fossils can be more like the mold fossils where an imprint is formed made in sediment or a rock.

Detailed explanation-2: -Fossils are rarely the original unchanged remains of plants or animals. Fossil formation begins when an organism or part of an organism falls into soft sediment, such as mud. The organism or part then gets quickly buried by more sediment.

Detailed explanation-3: -Sometimes when an animal dies and its body decays, it can leave an imprint in the sediment. If this imprint fills in with minerals from sediment and groundwater, it can harden to form a fossil. This fossil is called a cast fossil. The fossilized imprint is called a mold fossil.

Detailed explanation-4: -We find molds where an animal or plant was buried in mud or soft soil and decayed away, leaving behind an impression of their bodies, leaves, or flowers. Casts are formed when these impressions are filled with other types of sediment that form rocks, which take the place of the animal or plant.

Detailed explanation-5: -FOSSIL CASTS are found when a fossil mold underground is filled with sediment to form a fossil in the actual shape of the animal bones! Instead of being made of actual bone, fossil casts are made of hardened sediment (rock!)