Match the words with their defining feature.

_____	osteoblast	a. conveys excitatory signal
_____	myofibril	b. in the hands
_____	myoglobin	c. bone-forming cell
_____	knee	d. main thin filament protein
_____	actin	e. produces blood cells
_____	red marrow	f. donates phosphate to ADP
_____	metacarpal	g. binds and releases oxygen
_____	T tubule	h. a synovial joint
_____	creatine phosphate	i. composed of sarcomeres

To match: The each term with their suitable description.

Osteoblast - c. bone-forming cell

Bones are the specialized connective tissues that surround the living cells by a collagen-rich matrix, hardened by phosphorus and calcium. There are mainly three types of bone cells: Osteoblasts, Osteocytes and Osteoclasts. The osteoblasts are the bone builders that help to synthesize the bones. They can also secrete the matrix components.

Myofibril- i. composed of sarcomeres

The myofibrils are the thread-like parts of the muscle fibers. It contains the sarcomeres, which are the contractile units that are connected end to end. Myosin is a type of motor protein which is present in the myofibrils of the muscle fibers.

Myoglobin- g. binds and releases oxygen

The muscle fibers can be classified mainly into two types depending upon their ability to speed up the conversion of ATP to ADP by the myosin. They are slow fibers and fast fibers. The fast fibers include the white muscle fibers. The red fibers can be either slow fibers or fast fibers. These red fibers mainly depend upon the aerobic respiration. They lack mitochondria and possess myoglobin, which are the proteins that help to bind and release the oxygen.

Knee- h. a synovial joint

The structures that help to attach between the bones in our body for the movement are collectively called as joints. The joints are mainly classified into three types: cartilaginous joints, synovial joints, and fibrous joints...