The following are major steps in the process of intramembranous ossification. 1. Clusters of osteoblasts form osteoid that becomes mineralized.
2. Osteoblasts differentiate within mesenchymal connective tissue.
3. Spicules of bone radiate out from the ossification centers.
4. Mesenchymal cells aggregate.
The correct order for these events is 2, 3, 1, 4. 4, 2, 1, 3. 2, 1, 3, 4. 4, 1, 2, 3.

The correct order for these events is 4, 1, 2, 3.

4.) Mesenchymal cells aggregate.

1.) Clusters of osteoblasts form osteoid that becomes mineralized.

2.) Osteoblasts differentiate within mesenchymal connective tissue.

3.) Spicules of bone radiate out from the ossification centers.

Explanation:

Ossification is defined as the process through which bone is formed by osteoblasts. The secretions of collagen molecules and ground substances, mainly proteoglycans by these osteoblasts brings about bone production. There are two types of ossification they are:

--> intramembranous and

--> endochondral ossification.

Intramembranous ossification involves the development of bone from mesenchymal connective tissues. This process brings about the formation of the bones of the skull, flat bones of the face and the clavicle. There are 4 major steps that are involved in the process of intramembranous ossification, these include:

--> Aggregation of the mesenchymal cells: These cells group together into clusters to form the ossification center.

--> Osteoblasts form osteoid: Clusters of osteoblasts form osteoid that becomes mineralised leading to the formation of osteocytes.

--> Osteoblasts differentiate within mesenchymal connective tissue: This leads to formation of trabecular matrix and periosteum.

--> Development of new bone: Spicules of bone radiate out from the ossification centers. Compact bone develops superficial to the trabecular bone, and crowded blood vessels condense into red marrow.