Which of the following is NOT a characteristic of connective tissues in general?

A) Connective tissues contain an abundance of extracellular matrix.
B) The cells are packed tightly together, as they are in epithelial tissues.
C) The ground substance can vary from liquid to solid.
D) Most connective tissues are well-supplied with blood vessels.
E) All of these are characteristics of connective tissues in general.

Connective tissues are characterized by having an abundance of extracellular matrix and their cells are not packed tightly together like epithelial tissues. Connective tissues have a ground substance that can vary from liquid to solid, and not all connective tissues are well-supplied with blood vessels. Therefore, the only option that is not a characteristic of connective tissues in general is B, which states that the cells are packed tightly together.