Question

Why growth of bone is bi directional and cartilage is unidirectional and what is mean of uni and bidirectional

Answer 1

The bone grows in thickness from both the sides because of Endosteum which is present in the outer long bones of the marrow cavity which consists of osteoblasts and white fibrous tissues.

So the growth in both sides is called the bidirectional growth, whereas the case is not the same for cartilage.

Bidirectional growth is the growth from both sides and unidirectional is the growth from one side.

Answer 2

Answer:Bidirectional Growth of bone and unidirectional growth of catilage.

Explanation:the outer layerof bone is called periosteum-"it produces bone cells toward the inner side ".

there is a marrow cavity in bone .the layer of this cavity is called endosteum.Inside marrow cavity is bone marrow which produces Blood cells .Outer layer of this cavity ,as i told earlier-endosteum ,produces bone cells toward outside .

simply,periosteum produces bone cells toward inner side and inner layer endosteum produce bone cells toward outer side .

this growth is called bidirectional

.....

Cartilage growth is unidirectional because

the outer layer of cartilage called pericondrium gives rise to cartilage cellstoward inner side .and there is no inner layer in catilage unlike bone to produce new catilage cells toward puter side