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Part A Myofibrils are __________. e)None of the listed responses is correct. Par

ID: 323326 • Letter: P

Question

Part A

Myofibrils are __________.

e)None of the listed responses is correct.

Part B

During contraction of a sarcomere, what happens to the A band?

e) None of the listed responses is correct.

Would it be d or e? because nothing happens during contraction the A band sames the same size?

a)the basic contractile units of skeletal muscle tissue b)the contractile proteins located within a muscle cell c)the boundaries of individual sarcomeres d)specialized contractile organelles found in muscle cells

e)None of the listed responses is correct.

Part B

During contraction of a sarcomere, what happens to the A band?

a)It disappears. b)It shortens, because the myosin myofibrils (thick filaments) shorten. c)The pull of actin filaments causes it to lengthen. d)The A bands overlap, due to the pull of the thin filaments on the thick filaments.

e) None of the listed responses is correct.

Would it be d or e? because nothing happens during contraction the A band sames the same size?

Explanation / Answer

Answers : The correct answer is D (specialized contractile organelles found in muscle cells)

Explanation : Myofibrils are about 2 micrometers in diameter and extens the entire length of muscle fiber. Their prominant striations make the entire skeletal muscle fiber appears striated.