Who proposed the ‘Signal hypothesis’ meant for the biosynthesis of secretory type of proteins?

Where is the endoplasmic reticulum found within the cell?

The main function of dictyosomes is:

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: The primary function of the Golgi apparatus is to package the materials made by the endoplasmic reticulum and deliver it to intracellular targets and outside the cell.
Reason $(R)$: Vesicles containing materials made by the endoplasmic reticulum fuse with the cis face of the Golgi apparatus,and they are modified and released from the trans face of the Golgi apparatus.
In the light of the above statements,choose the correct answer from the options given below:

The fine network of single unit membrane distributed extensively throughout the cytoplasm in a cell is referred to as

The difference between rough endoplasmic reticulum and smooth endoplasmic reticulum is due to the presence of $........$.