A nucleus. Hope this helps.
The answer is copper. Nonrenewable resources are those that cannot be readily/naturally replaced at rates that match those of consumption (an aspect that allow renewable resources to be sustainable). Copper are made deep in earth at very slow rates hence do not readily renew themselves. Organisms, on the other hand die, and are naturally replaced by offspring.
It is most affected in the surface zone.
Answer:
The star could also be said to be 360 Million Million miles from the earth's sun.
Explanation:
A light year equals 9.4607 × 
km.
This is also approximately 6 Million Million Miles.
If we expressed the answer in miles, then we have to multiply 6 by 60.
This is equals to 360.
Therefore, 60 Light years is approximately 360 Million Million miles.
Cheers!
Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.
So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.
