Chapter Questions
A disadvantage of an exoskeleton is that ita. cannot protect an animal's internal organs.b. must be periodically shed, leaving the animal in a vulnerable state.c. does not provide any flexibility for the ease of movement of an animal.d. is a soft, easily damaged structure.cannot protect the outside of the body surface.
Which, if any, of the following is not a function of the vertebrate skeleton?a. structural supportb. protection of internal organsc. $\mathrm{Ca}^{2+}$ reserved. blood cell productionAll of the above are functions of the vertebrate skeleton.
The protein that provides strength and flexibility to bone isa. actin.c. myoglobin.e. elastin.b. myosin.d. collagen.
Which of the following statements is true?A. A muscle fiber is a collection of cells embedded in connectivetissue.b. A sarcomere contains both actin and myosin molecules arranged in a parallel fashion.c. The role of $C a^{2+}$ in contraction is to bind to tropomysin.d. Myofibrils are individual muscle cells.c. The I band of a sarcomere is the region where thin and thick filaments overlap.
The function of ATP during muscle contraction is toa. cause an allosteric change in myosin so it detaches from actin.b. provide the energy necessary for the movement of the cross-bridge.c. expose the myosin-binding sites on the thin filaments,d. do all of the above.e. do a and b only.
The function of $\mathrm{Ca}^{2+}$ in skeletal muscle contraction is toa. cause an allosteric change in myosin so it detaches from actin.b. provide the energy necessary for the movement of the cross-bridge.c. expose the myosin-binding sites on the thin filaments.d. bind to tropomyosin.e. do a and c only.
Stimulation of a muscle fiber by a motor neuron occurs ata. the neuromuscular junction.b. the transverse tubules.c. the myofibril.d. the sarcoplasmic reticulum.e. none of the above.
Muscle fibers that have a high number of mitochondria, contain large amounts of myoglobin, and exhibit low rates of ATP hydrolysis are calleda. slow-glycolyticb. fast-glycolyticc. intermedialed. fast-oxidativec. slow-oxidative
Which of the following statements about movement and locomotion is false?a. Terrestrial animals and flying animals expend cnergy to provide lift.b. Swimming animals expend encryy to provide thrust but not lift.C. Flexors and extensors are examples of muscles called agonists.d. Flexors cause bersding at a joint.c. Extensors cause straightening of a limb.
For animals adapted to it, swimming is energetically the cheapest type of locomotion because ofa. streamlined body forms in aquatic organisms.b. slow speed of movement of some swimmers.c. buoyancy of water.d. a and c only.e. $a, b,$ and $c$