Final answer:
Blood is considered a connective tissue due to its matrix of plasma, and it contains red and white blood cells with functions akin to other connective tissues, such as transport and immune response.
Step-by-step explanation:
Blood is classified as a connective tissue because, like other connective tissues, it contains a matrix composed of the liquid called plasma. The cells within this matrix are primarily red blood cells (erythrocytes) and white blood cells (leukocytes). Red blood cells are crucial for the transport of oxygen and carbon dioxide, whereas white blood cells are key players in the immune response. Additionally, while most connective tissues contain fibers, blood is unique in that its matrix does not have fibers, designating it a fluid connective tissue alongside lymph.
Connective tissues are broadly categorized by the characteristics of their matrix and the types of fibers within. Relative to other connective tissues, blood's matrix is watery, enabling the circulation of cells, salts, nutrients, and proteins throughout the body, serving various physiological roles. It shares similarity with other connective tissues in function and structure by providing transport and protection, linking it to the core characteristics of connective tissue.