In mammals,the lower jaw is made up of ....................

Which of the following statements are correct with reference to the human endoskeleton?
$A$. Human skull is monocondylic.
$B$. The joint between any two adjoining vertebrae is a cartilaginous joint.
$C$. In human beings, the number of cervical vertebrae is seven.
$D$. All ribs except the last $2$ pairs are bicephalic.
$E$. The occipital bone of the skull is articulated with the atlas vertebra.
Choose the correct answer from the options given below:

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.

The total number of vertebrae in a rabbit is:

The bones found in an adult are present in the form of ........ in the embryo.

Which of the following pairs does not have corresponding bones in the human skeletal system?