Final answer:
The structure that does not match the cell type is 'E. Smallest cell are egg cells' because egg cells are actually among the largest cells in the human body, not the smallest.
Step-by-step explanation:
From the options provided, the description or structure that does NOT match the cell type is E. Smallest cell are egg cells. Sperm cells indeed have flagella to help them swim towards the egg cell. Nerve cells are characterized by their long, thin extensions that aid in transmitting nerve impulses over long distances. Epithelial cells come in a variety of shapes and can indeed be rectangular, although they also have other shapes depending on where they are located in the body. White blood cells have the ability to change shape which allows them to move throughout the body and engulf pathogens. However, the smallest cells are not egg cells; in fact, egg cells, or ova, are among the largest cells in the human body. The statement about egg cells is therefore incorrect.