i. A globular head with a short arm - It is called the heavy meromyosin (HMM). The head and short arm projects outwards at regular distance and angle from each other from the surface of a polymerised myosin filament and is known as cross arm. The globular head is an active ATPase enzyme and has binding sites for ATP and active sites for actin.
ii A tail. is the light meromyosin (LMM).
What is the rib cage made of ?
The thoracic vertebrae, ribs and sternum together form the rib cage.