Final answer:
The tissue type characterized by widely spaced cells separated by fibers and ground substance is connective tissue, which supports, binds, and protects other body tissues.
Step-by-step explanation:
The tissue type that consists of widely spaced cells separated by fibers and ground substances, and is the most variable and abundant, is connective tissue. Connective tissue's main role is to support, bind, and protect other tissues and organs of the body. Unlike epithelial tissue that lines body surfaces and cavities, or muscle tissue and nervous tissue that are responsible for movement and signal transmission, respectively, connective tissue includes a variety of cell types like tendon, cartilage, and bone, as well as blood which is considered a specialized connective tissue.