Correct answer: D. all of the above
I believe the answer is
A
The large-scale movement of waters in the basins of the ocean is known as ocean circulation. The wind mediates surface circulation and the sinking and cooling of water in the Polar Regions mediate deep circulation. The conduction of warm upper waters towards the poles from the tropic is done by surface circulation.
1. In the given question, if large amounts of water are supplemented in the Polar Regions as glaciers melt then the warm water will exhibit a more difficult time in flowing towards north.
2. The effect it could impart in the area is that the local temperature would increase more.
Answer:
C. tetanic contractions might occur, which would stop the heart's pumping action.
Explanation:
The absolute refractory period of the cardiac muscle action potential refers to the time interval when the voltage gated sodium channels are inactivated. The absolute refractory period lasts ~180 msec. The action potential lasts 200-220 msec.
The refractory period of cardiac muscle is dramatically longer than that of skeletal muscle. This prevents tetanus from occurring and ensures that each contraction is followed by enough time to allow the heart chamber to refill with blood before the next contraction.
In order words, It is important for the cardiac muscle cells to have a longer refractory period, because if they were short like the skeletal muscles, the heart could enter tetanic contraction/summation which is when muscle is stimulated so rapidly that it does not have a chance to relax at all between stimuli.
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