A sarcomere is the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction. The most popular model that describes muscular contraction is called the sliding filament theory.
Coal is considered a non renewable source because the earth cannot replenish it.
The two contrasts between seagulls and wild geese are migration and their sizes. One way they are similar is that they can both fly for great distances. The other way is that they are similar is that are both very large in size. The correct answer is A.
