A muscle fiber contains many myofibrils, which are cylinders of muscle proteins. These proteins allow a muscle cell to contract. Myofibrils contain two types of filaments that run along the long axis of the fiber, and these filaments are arranged in hexagonal patterns. There are thick and thin filaments.hese proteins allow a muscle cell to contract. Myofibrils contain two types of filaments that run along the long axis of the fiber, and these filaments are arranged in hexagonal patterns. There are thick and thin filaments.
Cocklebur (Xanthium strumarium L.) is a large, annual broad-leaved weed with an erect, branched stem and broadly triangular leaves (Figure 1). The stem is rough-hairy, spotted with purple and up to 1.5 m high. The leaves are alternate on the stem, with toothed or lobed margins and rough-hairy surfaces.
A cockle is a small, edible, saltwater clam, a marine bivalve mollusc. Although many small edible bivalves are loosely called cockles, true cockles are species in the family Cardiidae.True cockles live in sandy, sheltered beaches throughout the world.The distinctive rounded shells are bilaterally symmetrical, and are heart-shaped when viewed from the end.ockles are capable of jumping by bending and straightening the foot. As is the case in many bivalves, cockles display gonochorism (the sex of an individual varies according to conditions), and some species reach maturity rapidly.