Connective tissues are made up of various structures and cells that contribute to their functions. However, one of the options provided in the question does not belong to connective tissues.

Option 1: Chondrocytes are cells that are present in connective tissues called cartilage. These cells are responsible for producing and maintaining the extracellular matrix of cartilage.

Option 2: Axons are not present in connective tissues. Axons are the long, slender projections of nerve cells that transmit electrical impulses to other cells or tissues. They are a part of the nervous tissue, not the connective tissue.

Option 3: Collagen fibers are one of the major components of connective tissues. They provide strength, support, and flexibility to the tissues. These fibers are produced by cells called fibroblasts, which are also present in connective tissues.

Option 4: Lymphocytes, a type of white blood cells, are also not found in connective tissues. Lymphocytes are mainly found in lymphoid tissues like lymph nodes, spleen, and tonsils. They play a crucial role in the immune response.

In conclusion, option 2, axon, is the correct answer as it is not present in connective tissues.