This is when. The sequence of events that result in the contraction of an individual muscle fiber begins with a signal—the neurotransmitter, ACh—from the motor neuron innervating that fiber. The local membrane of the fiber will depolarize as positively charged sodium ions (Na+) enter, triggering an action potential that spreads to the rest of the membrane will depolarize, including the T-tubules. This triggers the release of calcium ions (Ca++) from storage in the sarcoplasmic reticulum (SR). The Ca++ then initiates contraction, which is sustained by ATP (Figure 1). As long as Ca++ ions remain in the sarcoplasm to bind to troponin, which keeps the actin-binding sites “unshielded,” and as long as ATP is available to drive the cross-bridge cycling and the pulling of actin strands by myosin, the muscle fiber will continue to shorten to an anatomical limit.
Pretty sure it’s indigenous species
C.
<span>The new knowledge is used to reevaluate the theory.
When newer information is found on something, the theory is changed and updated based on the more reliable info. </span>
Answer is B. The number of the question that should be considered next. Let's say your organism has a dorsal fin, then you would go to 5. Then you choose a or b depending on the location of the tail. Let's choose 5a for now. Across from it says 6, so you go to 6
