Biology

Robert J. Brooker

Chapter 45

Muscular-Skeletal Systems and Locomotion - all with Video Answers

Educators

Chapter Questions

Problem 1

A disadvantage of an exoskeleton is that it
a. 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.
e. cannot protect the outside of the body surface.

Norma Kimmel

Norma Kimmel

Numerade Educator

Problem 2

Which, if any, of the following is not a function of the vertebrate skeleton?
a. structural support
b. protection of internal organs
c. Ca2+ reserve
d. blood cell production
e. All of the above are functions of the vertebrate skeleton.
3. The protein that provides strength and flexibility to bone

Norma Kimmel

Numerade Educator

Problem 3

The protein that provides strength and flexibility to bone is
a. actin.
b. myosin.
c. myoglobin.
d. collagen.
e. elastin.

Christina Sorrentino

Christina Sorrentino

Numerade Educator

Problem 4

Which of the following statements is true?
a. A muscle fiber is a collection of cells embedded in connective
tissue.
b. A sarcomere contains both actin and myosin molecules arranged in a
parallel fashion.
c. The function of Ca2+ in contraction is to bind to tropomysin.
d. Myofibrils are individual muscle cells.
e. The I band of a sarcomere is the region where thin and thick
filaments overlap.

Norma Kimmel

Numerade Educator

Problem 5

The function of ATP during muscle contraction is to
a. cause an allosteric change in myosin so it detaches from actin.
b. provide the energy necessary for the movement of the crossbridge.
c. expose the myosin-binding sites on the thin filaments.
d. do all of the above.
e. do a and b only

Norma Kimmel

Numerade Educator

Problem 6

The function of Ca2+ in skeletal muscle contraction is to
a. cause an allosteric change in myosin so that 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. stimulate an action potential in the muscle fiber.
e. do a and c only.

Norma Kimmel

Numerade Educator

Problem 7

Stimulation of a muscle fiber by a motor neuron occurs at
a. the neuromuscular junction.
b. the transverse tubules.
c. the myofibril.
d. the sarcoplasmic reticulum.
e. none of the above.

Christina Sorrentino

Christina Sorrentino

Numerade Educator

Problem 8

Muscle fibers that have a large number of mitochondria, contain large amounts of myoglobin, and exhibit low rates of ATPase activity are called _____ fibers.
a. slow-glycolytic
b. fast-glycolytic
c. intermediate
d. fast-oxidative
e. slow-oxidative

Norma Kimmel

Numerade Educator

Problem 9

Which of the following statements about movement and locomotion is false?
a. Terrestrial animals and flying animals expend energy to provide lift.
b. Swimming animals typically expend energy to provide thrust but
not lift.
c. Flexors and extensors are examples of muscles called agonists.
d. Flexors cause bending at a joint.
e. Extensors cause straightening of a limb.

Norma Kimmel

Numerade Educator

Problem 10

For animals adapted to it, swimming is energetically the cheapest form of locomotion because of
a. the streamlined body forms of aquatic animals.
b. the slow speed of locomotion of many swimmers.
c. the buoyancy of water.
d. a and c only.
e. a, b, and c.

Norma Kimmel

Numerade Educator