Answer:
Oil Immersion Higher magnification means the light is bent more. At a certain point, the light is bent so much that it can't make it through the objective lens. At that point – usually around 100x for standard lab microscopes – you'll need to put a drop of oil between your specimen and the objective lens.
Explanation:
The correct answer is that "t<span>roponin holds the tropomyosin in place on the actin".
In excitation-contraction coupling, tropomyosin prevents the interaction between actin and myosin in resting muscles. In the event of excitation, there is release of calcium from the sarcoplasmic reticulum wherein the troponin will bind this calcium and will release tropomyosin and expose myosin enabling it to attach to actin and therefore facilitating muscle contraction.</span>