Give a scenario where a cell may need to perform a form of endocytosis and exocytosis

A scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules.
A scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell. The movement of macromolecules of polysaccharides or proteins out of or into the cell is known as Bulk transport.
Bulk transport is of two types which include endocytosis and exocytosis whereby both require an expenditure of energy. Exocytosis materials are being exported out of the cell via secretory vesicles.
Golgi complex they do package macromolecules into transport vesicles which travel to and spill its content out of cells. Exocytosis is very much important in the expulsion of waste materials out of the cell and also in products secretion. Endocytosis is the process where materials move into the cell.
 Endocytosis is divided into the three types which include pinocytosis, phagocytosis, and receptor-mediated endocytosis.

Covalent bond is the correct answer