In the provided passage, the blanks can be filled with terms that describe the functions of the rough endoplasmic reticulum (RER) and Golgi apparatus. The correct terms would likely be:
- synthesized (for the rough endoplasmic reticulum): The rough endoplasmic reticulum is primarily involved in synthesizing proteins.
- transported/modified (for the Golgi apparatus): The Golgi apparatus is responsible for modifying, sorting, and transporting proteins.
Thus, the completed passage would read:
"Proteins are important molecules that are synthesized in the rough endoplasmic reticulum and transported/modified in the Golgi apparatus, which have parts to play in the system."
Choose the answer choice that includes "synthesized" for the RER and "transported" or "modified" for the Golgi apparatus.