The layer of cells that secretes enamel of tooth is

$A$ baby boy aged two years is admitted to play school and undergoes a dental check-up. The dentist observed that the boy had twenty teeth. Which teeth were absent?

Which layer of the alimentary canal wall is responsible for peristalsis?

Liver is located on . . . . . . in the human body.

Identify the parts $A$ and $B$ from the given cross-sectional diagram of the alimentary canal.

The stomach of ruminants is mainly divided into four parts,but in a camel,which one part is missing?