Answer
The combining form endo means in (or within).
Work Step by Step
An example of the use of this form is in the term endocytosis.
"Endo" means "in" or "into" and "cytosis" refers to a cellular process. Endocytosis, transcytosis and exocytosis are three terms that uses the form -cytosis. Endocytosis is the process of taking substances into the cell; transcytosis is the process of moving substances across a cell--captured on one side, taken across and extruded on the other side; exocytosis is the process of moving substances out of a cell. In these three processes, vesicles are very important.
