Q4. In NCERT’s general description: ribs are called bicephalic because they have two articulation surfaces at the dorsal end. Are both true, and does the reason explain the assertion?
Yes, within NCERT’s general description (page 225), the reason explains the term. Anatomically it is not true of every rib; for example, the 11th and 12th have a single articular facet.
Q5. Name the three ear ossicles.
The malleus, incus and stapes (NCERT page 224).
Q6. Which part of the scapula forms the shoulder joint with the humerus?
The glenoid cavity, below the acromion (NCERT page 226).