Answer:
The direct conversion of mesenchymal tissue into bone is called i<u><em>ntramembranous ossification</em></u> .The process by which a cartilage intermediate is formed and replaced by bone cells is called <em>endochondral osssification.</em>
Explanation:
Intramembranous ossification is one of the two essential process during the fetal development of the gnathosome skeltal system by which rudimentary bone tissue is created. It is the process of bone development from fibrous membranes. It is involved in the formation of the flat bones of the skull, mandible and the clavicle. This type of ossification also helps in healing of bone fractures.
Endochondral Osssification: Method of forming a bone through cartilage intermediate. It is also involved in the formation of long bones.
Due to being able to develop immune enzymes or toxins to fight and survive
Pro-metaphase is when the spindle forms. If that is not an option then it would be metaphase.
