Question 1

Which of the following best describes the role of calcium ions ($$\mathrm{Ca$$^{2+}$$}) in $$skeletal muscle contraction?

Accepted Answer

They bind to proteins on actin, exposing myosin binding sites and allowing cross-bridge formation.

Question 2

A patient is unable to produce acetylcholine at the neuromuscular junction. Which step in muscle contraction would be directly affected?

Accepted Answer

Release of calcium ions from the sarcoplasmic reticulum

Question 3

Which of the following is the correct sequence of events in the sliding filament model of muscle contraction?

Accepted Answer

Myosin binds to actin → Power stroke → ATP binds to myosin → Myosin detaches from actin

Question 4

Which structure is considered the functional unit of skeletal muscle contraction?

Accepted Answer

Sarcomere

Question 5

A muscle fiber is stimulated at a high frequency, resulting in a sustained contraction. What is this phenomenon called?

Accepted Answer

Tetanus

Question 6

Which of the following best explains why arthropods must molt their exoskeletons?

Accepted Answer

Exoskeletons cannot expand, so they must be shed for the animal to grow.

Question 7

Which type of skeletal system is found in earthworms and is essential for their movement by peristalsis?

Accepted Answer

Hydrostatic skeleton

Question 8

A person is unable to fully extend their arm at the elbow. Which type of joint is most likely affected?

Accepted Answer

Hinge joint

Question 9

Which of the following is NOT a function of the human skeletal system?

Accepted Answer

Transmission of nerve impulses

Question 10

During muscle contraction, what happens to the length of the sarcomere?

Accepted Answer

It decreases

Question 11

Which of the following best describes a motor unit?

Accepted Answer

A single motor neuron and all the muscle fibers it controls

Question 12

Which of the following is a correct statement about antagonistic muscle pairs?

Accepted Answer

One muscle contracts while the other relaxes to produce movement.

Question 13

Which of the following is a real-life example of a hydrostatic skeleton?

Accepted Answer

The body of an earthworm

Question 14

Which of the following is the primary immediate source of energy for muscle contraction?

Accepted Answer

ATP

Question 15

A genetic mutation prevents the formation of Z lines in muscle fibers. Which process would be most directly affected?

Accepted Answer

Attachment of thin filaments

Question 16

Which of the following best explains why vertebrate endoskeletons can grow with the animal?

Accepted Answer

They are composed of living tissue that can be remodeled and expanded.

Question 17

Which of the following is a correct pairing of joint type and location in the human body?

Accepted Answer

Hinge joint: elbow

Question 18

Which of the following best describes the relationship between the number of motor units recruited and the strength of muscle contraction?

Accepted Answer

The more motor units recruited, the stronger the contraction.

Question 19

Which of the following is a real-world example of an animal using an exoskeleton for movement and protection?

Accepted Answer

A grasshopper

Question 20

Which of the following best explains why the sarcomere shortens during muscle contraction?

Accepted Answer

Thin filaments slide toward the M line, pulling Z lines closer together.

Sensory and Motor Mechanisms: Muscle, Skeletal Systems, and Locomotion

Study Guide - Practice Questions