Myofibrils are the building blocks or contractile unit of each muscle fiber. The tiniest functional unit of skeletal muscle, the sarcomere, is found in the myofibrils and is made up of protein filaments: actin (thin) and myosin (thick).
Each cell contians 23 pairs of chromosomes
Secondary Succession<span>
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Answer:
Cells are sometimes referred to as "life's atoms" because there the basic units of life. All cells are surrounded by a structure called the cell membrane — which, serves as a clear boundary between the cell's internal and external environments.