Final answer:
The pair of globular heads of myosin II contains ATP-binding sites and actin-binding sites. Myosin II is a protein that makes up thick filaments in muscle fibers and plays a role in muscle contraction.
Step-by-step explanation:
The pair of globular heads of myosin II contains ATP-binding sites and actin-binding sites.
In more detail, myosin II is a protein that makes up thick filaments in muscle fibers. The heads of myosin II are located on either side of the thick filament, where they overlap with thin filaments composed of actin. The myosin heads contain ATP-binding sites, which allow them to bind and hydrolyze ATP, providing the energy for muscle contraction. They also contain actin-binding sites, which allows them to interact with actin filaments during the contraction cycle.