Coccygeal bone is formed by the fusion of ......... bones in man.

In mammals,the number of cervical vertebrae is

The head of the rib which articulates with the transverse process of thoracic vertebrae is called

Red bone marrow is present in

In humans,out of $X$ pairs of ribs,only $Y$ pairs are true ribs. Select the option that correctly provides the values of $X$ and $Y$ and their explanation.

Which statement is correct for vertebrochondral ribs in human?