Question

question 5 of 10
which evidence of past life contains the actual remains of an organism?
a. a cast fossil of an ancient mollusk
b. the petrified remains of a tree
c. a fossilized footprint
d. an insect trapped in amber

Explanation:

• A. Cast fossil: A cast fossil is a mold filled with sediment or minerals. It is not the actual remains of the organism. For example, a cast fossil of a mollusk is formed when the original mollusk decays and leaves an impression that gets filled.
• B. Petrified remains: Petrified wood (remains of a tree) is formed through a process of mineral replacement. The original organic material is replaced by minerals over time, so it is not the actual unchanged remains.
• C. Fossilized footprint: This is a trace fossil. It shows evidence of an organism's activity (like walking) but is not the organism itself.
• D. Insect in amber: Amber is fossilized tree resin. When an insect gets trapped in resin, the resin hardens. The insect inside is preserved in its actual form (with some possible minor chemical changes over time, but it is the actual remains of the organism).

Answer:

D. An insect trapped in amber