Answer:
The cell structures which can be seen missing from Clara's model are:
Ribosomes: Ribosomes can be described as the site where the synthesis of a protein takes place. Ribosomes are the structures where the process of translation occurs. The ribosomes which are involved in the synthesis of proteins are attached to the rough endoplasmic reticulum which is also missing in Clara's model.
Golgi Complex: Golgi complex is the site where the modification and packaging of proteins occurs. Thse modofications allow the protein to be transported outside of a cell to where it is required.