Activation of muscle contraction could be a speedy event that's initiated by electrical activity within the surface membrane and transversal (T) tubules. This can be followed by unharness of metal<span> from the inner membrane system, the sarcoplasmic reticulum.
</span>Nervous stimulation causes a depolarization<span> of the muscle membrane (sarcolemma) </span>that<span> triggers </span>the discharge<span> of </span>calcium<span> ions from the sarcoplasmic reticulum.</span>
Regulation of opening and closing of stomata
Plants and trees use photosynthesis
You could have made sure the books were the same weight and your friends could have done it at the same time as you