Patches of fibrocartilage formed in the healing of a fracture are called , whereas the bony collar formed around the fracture is called .

Patches of fibrocartilage formed in the healing of a fracture are called soft callus, whereas the bony collar formed around the fracture is called hard callus.

Explanation:

In the fibrocartilage or soft bone callus phase, the necrotic bone is removed by osteoclastia and dead soft tissues are being removed by macrophages. The fibroblasts are activated and a granulation tissue is generated that supposes the appearance of new vessels and, with them, the arrival of more connective tissue cells. A tissue called fibrous callus or fibrocartilage begins to form, composed of a poorly structured amalgam of fibrous tissue, cartilage, and amorphous bone.In hard callus, bone and later cartilage are deposited in the growing historical mass. The two collars of callus,  fixed to the bone at some distance from the fracture, they grow upwards and towards each other, forming an arc  on focus.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."