If the cross-bridges bind to actin, they will pivot in such a way to cause the actin filaments to slide. This pivoting action causes the actin filaments to slide _.
Correct answer: A. Closer together
- A. Closer together
- B. Farther apart
- C. Towards the Z-line
- D. Both B and C
Explanation
During a cross bridge cycle, the actin and myosin filaments slide inwards towards the centre of the sarcomere and the distance between adjacent Z lines decreases as a result. B and C mean the same thing - that the filaments slide away from the centre of the sarcomere, which is obviously incorrect.
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About Support and Movement
Support and movement covers the axial and appendicular skeleton, bone structure, joints and the arrangement of skeletal muscles. Muscle contraction is explained through actin, myosin, sliding filaments, calcium ions and ATP, while arthritis is distinguished as a disorder of joints rather than a normal part of movement.
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