Final answer:
The statement that ribosomes are the site of final protein processing for delivery outside the cell (option D) is not true. Ribosomes are involved in protein synthesis but the final processing occurs in the Golgi apparatus.
Step-by-step explanation:
The correct answer to the question is option D: Ribosomes are not the site of final protein processing for delivery outside of the cell. Ribosomes are crucial for protein synthesis, where they translate the genetic code provided by mRNA into a polypeptide chain. Here are the true statements about ribosomes:
- A. Ribosomes contribute to the rough appearance of the rough endoplasmic reticulum under a microscope.
- B. Ribosomes are composed of RNA and protein, and consist of two subunits, a large subunit and a small subunit.
- C. Ribosomes are present in both prokaryotic cells and eukaryotic cells.
It is the Golgi apparatus and not ribosomes that further processes proteins for secretion or delivery outside the cell.