All carbohydrates, including sugar, therefore contain the same three elements:carbon<span>, </span>hydrogen<span> and </span>oxygen<span>.</span>
Answer:
The prolonged electrical depolarization of cardiac muscle cells -that occurs during contraction- is due primarily to the persistent influx of calcium ion
Explanation:
The action potential of the heart muscle is longer with respect to skeletal muscle (around 300 milliseconds), and this is due to the activity of calcium (Ca⁺⁺ ) in the intracellular compartment.
The initial depolarization of cardiac muscle fiber depends on the entry of sodium (Na⁺) into the cell. However, for the action potential to occur and be maintained, Ca⁺⁺ must increase its cytoplasmic levels, which depends on:
- The increase in intracellular sodium induces the release of Ca⁺⁺ from the sarcoplasmic reticulum.
- Calcium entry from the extracellular space through the voltage dependent Ca⁺⁺ channels.
- The entry of extracellular Ca⁺⁺ causes the release of more Ca⁺⁺ ions by the sarcoplasmic reticulum, further increasing its intracellular concentration.
This is how the ion that guarantees the duration of the action potential of the cardiac muscle cell is the Ca⁺⁺.
Learn more:
Calcium, sodium and cardiac muscle cells brainly.com/question/4473795
Answer:
The correct answer will be- Crop rotation
Explanation:
When the growth of a type of crop which uses soil nutrients in abundance and then growing another crop in the same filed led to the decrease in the production of the next crop.
Thus farmers adapted to avoid such farming practices and developed a new practice which allowed the land to become fertile again so that the growth of next crop will not be affected.
The practice involved the planting of a crop on a piece of land then leaving the soil ploughed and unsown for a longer period of time and growing corp on another piece of land allowing the time to restore the nutrient content. This practice is known as "crop rotation".
Thus, crop rotation is the correct answer.
