Questions: The two main categories of square square are endocytosis and exocytosis.

The answer is: the two main categories of vesicular transport are endocytosis and exocytosis.

Explanation:

1. Endocytosis: This is the process by which cells internalize substances from their external environment. It involves the engulfing of external materials by the cell membrane, which then forms a vesicle containing the ingested material. There are different types of endocytosis, including phagocytosis (ingestion of large particles) and pinocytosis (ingestion of fluids and small molecules).

2. Exocytosis: This is the process by which cells expel materials to the external environment. It involves the fusion of vesicles containing the material with the cell membrane, releasing the contents outside the cell. This process is essential for the secretion of various substances, such as hormones and neurotransmitters.

In summary, vesicular transport is a crucial cellular mechanism for the movement of large molecules and particles into and out of the cell, facilitated by endocytosis and exocytosis.