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.
Clusters of flowers are called infloresence. I hope this helped!:)
The answer is D. A, B, and C all use photosynthesis, and make their own energy. A cougar relies on killing other animals to get energy. I hope this helps!
The answer would be chlorophyll
