Question

When a calcium ion binds to troponin:

Answer 1

*100% CORRECT ANSWERS

Question 1

Which of the following is not a function of skeletal muscle?

control blood vessel diameter

Question 2

Interactions between actin and myosin filaments are responsible for

muscle contraction

Question 3

At rest, active sites on actin are blocked by

tropomyosin molecules

Question 4

When energy reserves in a muscle are exhausted or lactic acid levels increase,

fatigue occurs and contraction is no longer possible

Question 5

The more movable end of a muscle is the

insertion

Question 6

Rigor mortis occurs in skeletal muscles a few hours after death. This is most likely due to

decreased ATP production and increased membrane permeability to calcium

Question 7

Each of the following changes in the skeletal muscle is a consequence of aging except  one. Identify the exception.

muscle fibers increase their energy reserves

Question 8

Because skeletal muscle contractions require large amounts of ATP, you would expect  skeletal muscle to have

a rich blood supply

Question 9

Since skeletal muscle movements are controlled by nerve impulses, in which of the  following would you expect the ratio of motor neurons to muscle fibers to be the  greatest?

muscles that control eye movements

Question 10

Which of the following activities would use isometric contractions?

maintaining upright posture

Question 11

A person whose genetic makeup makes him/her a better marathon runner than a sprinter  probably has ___ in his/her leg muscles.

slow fibers

Question 12

The area of the sarcomere containing the thick filaments is the

A band

Question 13

When a calcium ion binds to troponin,

tropomyosin moves out of the actin active sites

Question 14

The degree of relative movement is greater in the

pectoral girdle

Question 15

Based on what you've learned about how muscles are named, which muscle would you  expect to contract when grasping an object in the hand?

flexor digitorum

Answer 2

Answer:

Option (A).

Explanation:

Muscle contraction may be defined as the physiological process of the activation of tension generating sites that occur within the muscle fibers. Actin, myosin, troponin and other proteins are important for muscle contraction.

The calcium ion is important for the muscle contraction. The binding of calcium with troponin causes the movement of tropomyosin out of the grooves between the actin molecules during muscle contraction.

Thus, the correct answer is option (A).