skeletal muscle fiber morphology trait skeletal muscle size trait skeletal muscle cellular composition trait skeletal muscle fiber quantity 2009-05-07T03:19:34Z ATOL:0001691 The proportion or number of skeletal muscle fibers, the large multinucleated cells that make up the striated muscles connected at either or both extremities with the bony framework of the body. Trait.ontology VT:1000743 caripark skeletal muscle cell number skeletal muscle fiber number