(i) Ligaments connects bone to bone in humans. Following are the characteristic features of the ligament:

● Ligament is very elastic and flexible in nature.

● It is of considerable strength.

● It contains very little amount of matrix.

(ii) Simple squamous epithelium forms the inner lining of the alveoli. Following are the characteristic feature of the simple squamous epithelium:

● The cells are extremely thin and delicate.

● It forms a delicate, flat and thin lining.

(iii) Cell wall has the prominent middle lamella.

Features of the middle lamella:

● Middle lamella cements the two cell walls.

● It is found between the cell wall of fruits also.

● It is composed of cellulose, hemicelluloses and pectin.

(iv) Xylem components tracheids and vessels transport the water and minerals in the plants. Following are the characteristic feature of the xylem tracheids and vessels:

● Tracheids and vessels are dead elements of xylem.

● They have thick walls and are tubular structures.

● Tracheids and vessels provide unidirectional flow of water and minerals.