Classification. The following items are part of the cytoskeleton. Respond to the statements below with reference to these elements. This is a very visible structure in human sperm. a. Microtubules These make up the cell cortex. b. Microfilaments This structure is elongated by microfilaments. c. Intermediate filaments These fine fibers function in contraction. d. Motor proteins These molecules function like cellular freight trains. e. Cilium These temporary structures allow cells to engulf targets. f. Flagellum These are the most stable cytoskeletal elements. g. Pseudopods These form a dynamic scaffold for cellular processes. The coordinated movement of many of these stirs fluid around some cells..