GEOLOGY

Detailed explanation-1: -C.A mold fossil is just an impression in rock; a cast fossil is an impression that was filled in with minerals.

Detailed explanation-2: -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-3: -A fossil mold is the shape of an organism that remains in rock after the organism’s hard parts decay or dissolve. A fossil cast is a sort of replica of the original organism that is produced when a fossil mold fills with mineral-rich water and sediment that eventually harden in the shape of the organism.

Detailed explanation-4: -Like other fossils, molds and casts provide information about deceased organisms. They are a shape left behind by an organism, rather than a body part that has been directly preserved such as wood or bone.

Detailed explanation-5: -To be considered petrified, the cells of the original organism had to have been replaced by minerals via permineralization so that a record of the internal structures are preserved. This is in contrast to cast fossils where the entire original organism decomposed leaving a cavity which was then filled in with minerals.