MACROMOLECULES are large molecules, such as protein, commonly created by the polymerization of smaller sub-units called monomers.
The NUCLEAR PORE is a protein-lined channel in the nuclear envelope. The NUCLEAR PORE regulates the transportation of molecules between the nucleus and the cytoplasm. In eukaryotic cells, the nucleus is separated from the cytoplasm and surrounded by a nuclear envelope.
mRNA is synthesized by DNA during a process known as the TRANSCRIPTION. After the synthesis, the new molecule moves from the nucleus to the cytoplasm. It passes through the nuclear membrane through a NUCLEAR PORE. Then, it will later join with a ribosome, which is just coming together from its two sub-units, one large and one small.
Based on the information provided within the question it can be said that the term that best explains these "living fossils" is Phylogenetic niche conservatism. This refers to the tendency that a specific species has for retaining certain traits from the ancestors. Which explains why the living "cycads" are nearly identical to fossils.
