Final answer:
The statement that ribosomal parts can self-assemble in a test tube is true; the ribosome's large and small subunits can spontaneously combine to form a functional unit that synthesizes proteins.
Step-by-step explanation:
The statement that if you put all the parts of a ribosome into a test tube, they will self-assemble is True. Ribosomes consist of two main subunits, the large subunit and the small subunit. These units can indeed self-assemble under the right conditions since the subunits are capable of spontaneously coming together. Ribosomal RNA (rRNA) and proteins form these subunits, undergoing a process where they fold into the correct shapes and combine to form a functional ribosome, which during protein synthesis, assembles amino acids into proteins. This self-assembly is a fundamental aspect of the ribosome's function and is a key feature of molecular biology.