Troponin-tropomyosin molecules prevents a muscle contraction from occurring when the muscle is at rest.
<h3>What is
muscle contraction?</h3>
The activation of tension-producing regions within muscle cells results in muscular contraction. Because muscle tension can be created without changes in muscle length, such as when holding something heavy in the same position, muscle contraction does not always imply muscle shortening in physiology. Muscle relaxation, or the return of the muscular fibers to their low tension-generating state, occurs after a muscle contraction has finished.
Both length and tension can be used to characterize muscle contractions. If the muscle tension varies but the muscle length doesn't, the muscle contraction is said to be isometric. A muscle contraction is isotonic, however, if the tension in the muscle remains constant during the contraction.
To learn more about muscle contraction with the help of given link:
brainly.com/question/10115123
#SPJ4
Scientists have tried lots of different ways of predicting earthquakes, but none have been successful. They<span> haven't been able to find a signal for earthquakes( there is no obvious sign to say that an earthquake is coming very soon).</span> They do have a pretty good idea of where an earthquake is most likely to hit, but they still can't predict exactly when it will happen.
However, the probability of a future earthquake can be calculated, based on scientific data. Scientists estimate that the probability of a major earthquake occurring in the San Francisco Bay area over the next 30 years is 67%.
4.Metaphase
All of the chromosomes are aligned midway between the
spindle poles. A spindle is a dynamic network of microtubules that
attaches to and moves chromosomes during nuclear division. Microtubules
attach each chromatid to one of the spindle poles, and its sister to the
opposite pole.
The geologist time scale was formed when scientists studied rock layers and index fossils worldwide. With this information, they placed Earth's rocks in order by relative age. Later, radioactive dating helped determine the exact age of the divisons in the geologic time scale.
This scale is organized by the 4.6 billion years of earth's history into sections based on important changes seen in the geologic record. The largest intervals are called eons, with each eon containing many millions of years.
In precambarian time the processes that affect Earth's surface have lessened the erosion on the surface. Earth was being hit by meteorites every second. Now there is water erosion and there wasn't back then. The surface changes have lessened over time.