I believe the answer is b
Flagella and cilia have the exact same structures and functions, and the names merely indicate how many are present on a given cell. When found singly or in a pair, these cell protrusions are called flagella<span>.</span>
ATP is required for muscle contraction. Four sources of this substance are available to muscle fibers: free ATP, phosphocreatine, glycolysis and cellular respiration. A small amount of free ATP is available in the muscle for immediate use.
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